Question

Twice a number is decreased by 9, and this sum is multiplied by 4. The result is 8 less than 10 times the number. What is the number?

Answer 1

4(2n - 9) = 10n - 8

8n - 36 = 10n - 8

8n - 8n - 36 = 10n - 8n - 8

-36 = 2n - 8

-36 + 8 = 2n - 8 + 8

-28 = 2n

-28/2 = 2n/2

-14 = n