1.The total cost of a belt and a shirt is $112. The cost of the shirt is 3 times as much as that of the belt. Find the cost of the shirt.
let $x be the cost of the belt
x+3x = 112
x = cost of belt
therefore, 3x = cost of the shirt
2.If the sum of two consecutive odd numbers is 20, find the smaller number.
let x be the smaller number
x+(x+2) = 20
x = smaller number