Eight times the sum of a number and 9 is 7

Answer 1

x = the number

x + 9 = the sum of a number and 9

8(x + 9) = eight times the sum of a number and 9

8(x + 9) = 7

8x + 72 = 7

x = (7 - 72) / 8 = -65 / 8