9+2r=-2(1+r)-1

Solution for 9+2r=-2(1+r)-1 equation:

9+2r=-2(1+r)-1

We move all terms to the left:

9+2r-(-2(1+r)-1)=0

We add all the numbers together, and all the variables

2r-(-2(r+1)-1)+9=0


We calculate terms in parentheses: -(-2(r+1)-1), so:

-2(r+1)-1

We multiply parentheses

-2r-2-1

We add all the numbers together, and all the variables

-2r-3

Back to the equation:

-(-2r-3)


We get rid of parentheses

2r+2r+3+9=0

We add all the numbers together, and all the variables

4r+12=0

We move all terms containing r to the left, all other terms to the right

4r=-12

r=-12/4

r=-3