4(2r + 8) = 88
mutiply the bracket by 4
(4)(2r)(4)(8)= 8r+32
8r+32= 88
Move +32 to the other side
Sign changes from +32 to -32
8r+32-32= 88-32
8r= 88-32
8r= 56
divide by 8 for both sides
8r/8= 56/8
Cross out 8 and 8, divide by 8. Then becomes r
r= 7
Answer: r= 7