O/T I need a little Algebra help

Hello folks, I was wondering if maybe I could find a little help on 3 homework questions I am stuck on.

First one is 9x to the 4th power y to the -3rd power z to the 8th power divided by 12x to the -4th power and in parentheses y to the 7th power plus z to the 4th power with 0 power outside the parentheses on the right. The whole problem is surrounded by brackets like this [] to the -3rd power.

the second problem I can just type out is 2ab-{7ab-[2a-2ab-8(2b-ab)]}+ab
I just multiplied what was in the parentheses and pretended that the other brackets were not there since I think those were just thrown in to confuse me, and then combined like terms to get an answer of 2ab-2a-16b. Is that correct?

the 3rd problem I am stuck on is finding the area of a triangle with a base 2 inches and height of 4 inches?

Thanks in advance,

Can't really help with your 3 problems. The only real Algebra formula I remember from school is LogA+logB+logC+logD......+logZ equals Log Cabin

Is that a right triangle? (one corner is 90 Degrees) If so, figure a 2X4 rectangle, and divide by 2, so amswer would be 4 Sq. In. IF it is a Right Triangle..

I could tell you the answer, but them you would not learn anyhing.

I posted all the information given on the triangle problem. It has got to be just a simple ordinary triangle or the problem would have specified.
Thanks!

According to my 8th grade granddaughter your second problem is correct. She offered this: there is an order of operations for math problems.
work parentheses, exponents, multiply, divide, addition, subtration in this order. Area of triangle is 1/2 base times height. therefore 1/2 2 times 4 is 4 square inches. And we don't follow your first problem.
Good luck

On the triangle problem, look up the formula for the area of a triangle in your text and use that.

On problem 2, keep in mind that two negatives give a positive, but 3 negatives give a negative.

I'll give it a shot.
1. The expression (y to the 7th plus z to the 4th) raised to the zero power is equal to 1. That's because any quantity to the zero power is equal to one. So for this situation you may simply ignore that expression. Now, y to the -3 is in the numerator. Move it to the denominator (bottom of the fraction) and change it to y to the 3rd (drop the minus sign). In the same manner, move the x to the -4 from the bottom to the top of the fraction (the numerator) and change it to x to the 4th (drop the minus sign). Divide both the 9 and the 12 by 3. In other words, reduce the 9/12 to 3/4. Now the numerator is 3 x to the 8th z to the 8th. The denominator is 4 y to the 3rd. AND, all of that is inside of brackets and raised to the -3rd. Turn the fraction upside down (that is, write its reciprocal) and drop the minus sign of the 3rd power. Finally, raise each factor in the top and bottom of the fraction to the 3rd power. The answer is 64 y to the 3rd over 27 x to the 8th z to the 8th. I wish I was showing you face-to-face and on a chalkboard -- it sure would be easier!

2. On this one, start from the inside and work out. The biggest "trick" is remembering to distribute the minus signs throughout the various parentheses and brackets. Here we go:
2ab-{7ab-[2a-2ab-8(2b-ab)]}+ab becomes,
2ab-{7ab-[2a-2ab-16b+8ab]}+ab then,
2ab-{7ab-2a+2ab+16b-8ab}+ab and,
2ab-7ab+2a-2ab-16b+8ab+ab combine the like terms,
2ab-7ab-2ab+8ab+ab+2a-16b (I just rearranged them)
finally: 2ab+2a-16b is the answer. You were real close on that one! Looks like you missed a sign-change somewhere.

3. This one is much easier to explain. The area of a triangle is 1/2 times the base times the height. (A= 1/2 bxh) So your triangle area is 1/2 of 2x4, or 1x4, or even 2x2=4 square inches. You see, it doesn't matter whether you use half of the base and multiply by the height, or use half of the height and multiply by the base, or just multiply the base by the height and then take half of the product! It's a beautiful thing.

I sure hope this is helpful to you. Best of luck.
Tom

I am very much interested in how you get the answers.

In the first problem I know that -3 exponent has got to be distributed to everything in the problem, but my main question is do you do that before you do what is in the parentheses? I just did what I thought might be correct and ended up with 36864x to the 9th power z to the 24th power +43y to the 9th power divided by 576X to the 9th power and z to the 24th power.

The middle question I already provided the answer that I thought might be right, but I wanted varification if I was doing it right or not.

The 3rd question is something that was thrown in as a twist.

Thank you very much Tom! You sure were a big help. Its those odd brackets that were throwing me off track. I really appreciate the breakdown showing me how it is done. I agree a chalkboard would have been nice, but I think we did it! Now my homework is complete.

Pooh Bear (aka Fluff For Brains)

Tom, are you sure your exponesnts are correct for the x and y and z portions of the final simplification?

We didn't need all those fancy formulas when I was in school, the world wasn't so complicated back then. The "lever and fulcrum" theory explained how a pitch fork and scoop shovel worked.

My junior college calculus instructor always told us infinity-infinity is six. Love to tease my daughter with it.

Larry in Michigan

Those exponents needed to be multiplied by 3.

You are correct. I am wrong. All of the exponents DO need to be multiplied by 3. Good thing it wasn't MY homework! Tom

Since problem #1 started with the whole fraction raised to the minus 3 power, you could raise everything to the 3rd power as you have asked, but it is usually easier in the long run if you first look to see if the numbers can be reduced. You'll get the same answer either way. So it's just easier to reduce 9/12 to 3/4, than it is to raise the 9 and the 12 to the 3rd power, then have to figure out how to reduce 729/1728 . As for the negative exponent, that denotes the reciprocal. So, you can get rid of the minus sign in front of the "-3" by simply turning the whole fraction upside down. For example: (3/4) to the -2 power would be the same as (4/3) to the 2 power. Sorry that I forgot to multiply all of the exponents by 3 in the answer I gave you last night. No one should do Algebra at that time of day, let alone a retiree! -- Tom

I'm sorry , I can't help you with these problems..In fact, For me to count to 21....I've got to get "Necked".......Necked in Ohio quite often...

I really appreciated the help. Everything was right except those exponents and that was a slight oversight. Yes it was very late and I finished up that math and went to bed at 2:00AM myself. Good catch on the problem that I had the wrong sign. Where else was I going to get a tutor at that hour?

When I started to read the problem I must ask a question, is it 9x to the fourth power or is it 9 times x to the fourth power? Clarifying this point will change the answer.Let me know and I will simplify it for you.
If we say the problem looks like 9x^4 and the denominator is 12x^(-4) then the result should be (64y^9)/(27x^(24)*z^(24)) however if the original problem was (9x)^4 and (12x)^(-4) then I believe the answer should be y^9/(9^12*12^12*x^24*y^24). Man this would have been simple if we could have exchanged thoughts and processes in scientific notebook. Bud

I'm sorry you got algebra. I think if you are allergic to bras , you should stay away from them. The algebra may clear up then. Good luck with it.

If Mom was alive. Died in 2003 at 93. She got me through algebra in 9th and 10 grade and again with electrical apprenticeship. Also did algebra homework for my sons in 1982 and 83. Only member of her family with unbelievable math ability. Also good mechanic, carpenter, and all the other things mothers can do. Chosen in high school as likely to be a college professor, but got married instead. I sure miss her.

I got the answer to the first question wrong.
It should be:



I have the full solution worked out if you need to see it.

Pooh Bear