The sum of two numbers is 70. One number is 8 more than the other. What’s the smaller number?

Let x = the smaller number and x + 8 equal the larger number. Because the sum of the two numbers equals 70, you can express this mathematically as x + (x + 8) = 70. Now all you have to do is solve for x. Combine the like terms: 2x + 8 = 70. Then subtract 8 from both sides of the equation: 2x + 8 – 8 = 70 – 8, or 2x = 62. Divide both sides of the equation by two, and you find that x is equal to 31.