Question

I am doing some algebra homework and we are solving equations by expanding brackets. I was going along fine with the positive numbers however I am a bit stuck on these negative ones...
-(6-7)=2
-10(s+1)=-87

Appreciate it if you can help me solve these!

Answer 1

-10(s + 1) = -87 

The same way you do positive numbers, you do negative number. Multiply whatever is in the parenthesis by what's on the outside, which in this case is -10. So: 

-10*s + -10*1 = -87 
-10s + -10 = -87

To solve, first add -10 to both sides

-10s = -77 

next, divide both sides by -10

s = 7.7 

To check the answer, plug the solution into the original equation
-10(s+1) = -87
-10(7.7 + 1) = -87
-10(8.7) = -87
-87 = -87 

(for the first one, is there a variable involved?)

Answer 2

The first one is incomplete.

$-10(s+1)=-87\\ -10s-10=-87\\ -10s=-77\\ s=7.7$