Math CentralQuandaries & Queries


Question from Cynthia, a student:

How do I solve this problem?
If -1/3x + 7= 16, what is the value of 2x+1


Hi Cynthia.

Whatever you do to one side of the equation you have to do to the other. So change the left side of the equation and the right side at the same time. Transform the left side closer and closer to what you want.

I'll start you off:

-1/3x + 7= 16

First, I don't want the 7 there, so I subtract 7 from each side:

1/3x + 7 - 7 = 16 - 7 which simplifies to

1/3x = 9

Now I want to change the factor of 1/3 to a 2. That means I have to multiply by 6, because 6/3 = 2.

Can you complete this step and do the last step?
Stephen La Rocque.

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