solve the equation 2r -7=-1

Question

Need help solving this multi step equation for my homework n i cnt figure out how to do itmyself

Answer 1

Hi Lainie--

 

The idea is to get all your letter terms on one side of the =, and all the plain numbers (with no letters attached) on the other side.

 

So, starting with 2r - 7 = -1, you need to eliminate the "minus 7" from the left side. You can do that by adding 7 back onto that side, but it means you need to also add 7 to the other side to keep it balanced:

 

2r - 7 + 7 = -1 + 7

 

Which leaves you with 2r on one side, and positive 6 on the other:

 

2r = 6.  And if 2 "r's" are 6, then just 1 r is 3, so

 

r = 3

 

To check if you're right, you plug in to the original equation to see if it's true:

 

2 x 3, minus 7, = 6 - 7, which equals - 1. Check!

 

Hope this helps.

 

Matt in NY