Posted by Jmiah on October 03, 2002 at 10:06:46:
In Reply to: I'll do #1 posted by T.Gracken on October 02, 2002 at 20:02:59:
: : These are problems in my math book for which I got different answers than the answer key. However, I can not find my mistake, nor can I figure out how they got what they did. Please help!!
: : 1. (6/9)*2-9y=8(y-4+7)
: : My answer= [y=(5 12/51)]
: : Their answer= [y=(-68/51)]
: since you did not show any of your proceedure it is near impossible to point out your "flaw". However, I will attempt to explain the proper procedure and you can go from there...
: first: eliminate parenthesis (use distributive property)
: you get (6/9)*2-9y=8(y-4+7)
: =(2/3)*2 - 9y = 8y - 32 + 56 ...[I also reduced the 6/9 to 2/3 since I noticed it] ...yes there are also other things you could do BUT I DIDN"T!
: sorry...it just seems silly to learn all the little tricks...
: simplify each side as much as you can and you should get
: 4/3 - 9y = 8y + 24
: (add 9y to both sides and subtract 24 from both sides to get):
: 4/3 - 24 = 17y
: which is the same as
: -68/3 = 17y
: now divide both sides by 17 and you have
: y = -4/3
: NOTE!!!!!!!!! the answer you gave from the text (-68/51) reduces to -4/3. So tell your teacher to get a book that at least completes the problem so you know if you have the correct answer. [...unfortunately, your answer was not even close or we might have had a really good time with your teacher. they really can be confused if you you know the topic.]
: : 2. ([4*8-5=2]^2)-(3-6-(7^2)*9
: : My answer= [1285]
: : Their answer= [397]
: : If you see a flaw in the logic of either, please tell me.
Okay, here was my procedure.
(6/9)*2-9y=8(y-4+7)
(2/3)*2-9y=8(y-11)
4/3=17y-88
89 1/3=17y
y=60/51
But I think I just saw the problem. I wasn't supposed to add first was I? Thanx.