Question

S = a + b + c

Solve for b.

Answer 1

S - c - a = b or b = S - c - a ( same answer just written differently)

Explanation:

S = a + b + c move the unwanted exponents to the other side

S = a + b + c / - c

S - c = a +b / - a

S - c - a = b

Answer 2

`s=a+b+c` solve for b

Flip:

`a+b+c=s`

Add -a to both sides:

`a+b+c+-a=s+-a`

`b+c=-a+s`

Add -c to both sides:

`b+c+-c=-a+s+-c`

`\fbox{b = -a - c + s}`