Question 27220: I took my test and got a lot of answers wrong. He circled the correct answers but no matter what I try I keep getting mine. For example:
3(x-2)+7=2(x+5)
I distribute first, to get 3x-2+7=2x+10
I simplify to get 3x+5=2x+10 and then again to get x+5=10, then x=5, which is my answer. He circled 9 as the right answer. In fact, 5 isn't even an option (multiple choice). What am I doing wrong?? I keep getting 5 no matter how I do it.
Another is 11x-(6x-5)=40
I combine to get 5x-5=40, then simplify to get 5x=45, and again to get my answer : x=9
He has 7 circled as the right answer.
What am I doing wrong?
Thank you,
Sarah
Answer by rodriguezh2(15)   (Show Source):
You can put this solution on YOUR website! Sarah
For the first problem:
3(x - 2) + 7 = 2x + 10
Remember order of operations; First you must do what is in the parantheses
So: 3x - 6 + 7 = 2x + 10 (you forgot to multiply 3*2)
3x + 1 = 2x + 10 Now subtract 1 from both sides
3x = 2x + 9 Now subtract 2x from both sides
x = 9
For the second problem:
11x - (6x - 5) = 40 Subtract 11x - 6x
5x - 5 = 40 Add 5 to both sides
5x = 35 Divide 5 from both sides
x = 7
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