21=2(y+8)-7y

Solution for 21=2(y+8)-7y equation:

21=2(y+8)-7y

We move all terms to the left:

21-(2(y+8)-7y)=0


We calculate terms in parentheses: -(2(y+8)-7y), so:

2(y+8)-7y

We add all the numbers together, and all the variables

-7y+2(y+8)

We multiply parentheses

-7y+2y+16

We add all the numbers together, and all the variables

-5y+16

Back to the equation:

-(-5y+16)


We get rid of parentheses

5y-16+21=0

We add all the numbers together, and all the variables

5y+5=0

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

5y=-5

y=-5/5

y=-1