Need help figuring out 7x-5x+15=x+8?

Question

Struggling math student. Your assistance is appreciated

Answer 1

7x-5x+15=x+8

2x+15=x+8  Simplify

2x+15=x+8  Isolate x by subtracting it from both sides, to have the

-x         -x    variable on just one side of the equation

x+15=8        Subract 15 from both sides to solve for x

  -15  -15

x= -7            Answer.

7(-7)-5(-7)+15= (-7)+8       Check.

-49-(-35)+15=1

-49+35+15=1

-14+15=1

1=1

  

It is correct.

Answer 2

7x-5x+15=x+8

2x + 15 = x + 8

2x - x = 8 - 15

x = -7

Answer 3

7x- 5x = 2x subtract or add common numbers (sorry I forgot the term) that are on the same side of the equation. Then...

2x+15=x+8       move the x's to one side and the #'s to the other

-x  -15 -x -15     by subtracting or adding to both sides

x = -7              now x = - 7 after adding and subtracting

Hope this helps! :-)

Answer 4

The goal is to get all of the "x"s together on one side of the equation and all of the whole numbers together on the other side.  Once this is accomplished, we'll get a multiple of x down to just one x.  Whenever a chance is made to one side of the equation, it must be made to both.  

First, 7x-5x = 2x so you can simplify that portion of the equation immediately.  The equation then becomes 2x + 15 = x + 8.

Next, let's eliminate the whole numbers from one side of the equation.  It doesn't matter if you subtract 8 or if you subtract 15; whatever you do - do to both sides.  For example purposes, let's subtract 15. We'll do this to both sides so that the right side simply becomes "2x." Our equation is now 2x = x - 7.

Next, let's simplify the right side of our equation.  Do you see anything that can be "grouped" with a similar figure on the other side? I do, it's the x!  We have two x on one side and one x on the other (all positive).  How can we combine them?  We can combine them by subtracting one x from each side of the equation.  When we do that, our equation becomes x = - 7.

Though completing your homework for tomorrow's class (or even today's!) may be your current motivation, I urge you to try your hardest to understand what you're studying.  Math is a difficult subject where the next step always builds on the previous.  Strive to understand the meaning and you'll be far more successful than just striving to complete today's assignment.

Best of luck!

P.S.  There are multiple ways of arriving at the correct answer, which is why some replies have a different process than the others.

Answer 5

7x-5x=2x. So 2x+15=x+8. Subtract the x from the right side to the 2x on the left side. 2x-x+15=8. You want to get x on one side and the numbers on the other. Now, x+15=8. x+15-15 cancels out the fifteen on the left side. But to keep the equation equal, you have to subtract 15 to both sides. x+15-15=8-15.

x=-7

Answer 6

7x-5x+15=x+8

2x + 15 = x + 8

2x = x - 7

x = -7

Answer 7

First things first, subtract x & 8 from both sides so that the result =0.

Answer 8

x = -7

Answer 9

2x +15 = x+8

2x - x = 8-15

x = -7

Answer 10

2x + 15 = x + 8

2x - x = 8 -15

x =  -7