What is the answer to this question?

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4(8-y)=2y+16
asked Apr 13, 2014 in Math
edited Mar 25, 2014

+1 vote

4(8-y)=2y+16

I first multiply thing out on the left

32 - 4y = 2y + 16

With an equation, you can do any math operation on one side if you do the same thing on the other side. It is like a scale that stays balanced as long as you add the amount of weight on both sides.

I'm going to add 4y to both sides

32 - 4y + 4y = 2y + 16 + 4y

You can now combine the y's to simplify

32  = 6y + 16

Subtract 16 from both sides
32 - 16 = 6y + 16 -16

16 = 6y

Divide both sides by 6

16/6 = 6y/6

16/6 = y

or

y = 16/6

this can be simplified since 6 goes into 16 two times with a remainder of of 4/6 or 2/3

y = 2  2/3

in decimal it is about ~ 2.67

It is always a good idea to check your results so

4(8-16/6) = 2(16/6) + 16

Doing the math shows they are both equal, which validates the answer.

After a while you can do these much faster. I can even give you answer without writing anything down in my head, but best to do it all in small steps when you are a beginner. Over time you will get better at it.

answered Apr 13, 2014 by (21,080 points)