View Full Version : Algebra homework
sugartea
Mar 5, 2009, 04:07 PM
3(5x-4)=8x+2 answer=2
I am the father of an 8th grade boy who is having difficulty in algebra. Unfortunately Im not so good myself. His answer is 2 but he is not sure its right can you work the problem out so I can teach myself and hopefully teach him.
Curlyben
Mar 5, 2009, 04:10 PM
The actual answer isn't worth as many marks as showing the COMPLETE workings.
So best to teach him how to write everything down that he does for full marks.
As the problems get harder marks will be awarded for the method even if the result is incorrect.
XOXOlove
Mar 5, 2009, 04:29 PM
your son was correct. Here's how:
3(5x-4)=8x+2 you have to multiply the 3 by the 5x and the -4 to get:
15x-12=8x+2 then subtract the similar terms on both sides. Like this:
15x-12=8x+2
-8x -8x
this equals 7x-12=2 (the 8x cancels)
then add 12 on both sides:
7x-12=2
+12 +12
the 12x cancels so you are left with:
7x=14
divide by 7 on both sides so you can get x:
7x=14
--- ----
7 7
the 7 on the left cancels because it becomes 1
so x=14/7=2 hope this helped and wasn't too confusing :)
XOXOlove
Mar 5, 2009, 04:32 PM
sorry the numbers became kind of off centered when I submitted the answer. They were supposed to be on both sides of the equation.