There were 150 students at a dance. There were 16 more boys than girls. How many boys were there?

Set up two equations:

(1) b = g + 16
(2) b + g = 150

Substitute equation (1) into (2)
(g + 16) + g = 150

Combine like terms
2g + 16 = 150

Subtract 16 from each side
2g = 134

Divide each side by 2 to isolate g
g = 67

Substitute this into equation (1)
b = 67 + 16
b = 83