The sum of eight and three times a number is 53. Find the number.

Part one - write an equation

Part two - Solve it

Part one:

if we let x be the number, then equation is 8 + 3x = 53

part two

we subtract 8 form both sides to get 3x = 53 - 8 = 45

then divide both sides by 3 to get x = 15. the number is 15