Question

someone thinks of a number when he multiplied his number by 5 and subtracts 16 from the result he gets the same answer as when he adds 10 to his number and multiplies that result by 3 finder the number hes thinking of

Answer 1

Let's call his secret number 'M' (for mystery-number).

multiplied it by 5 . . . 5M
subtracted 16 from the result . . . 5M - 16

adds 10 to the number . . . M + 10
multiplies that result by 3 . . . 3(M+10)

Both processes produce the same results:

5M - 16 = 3 (M + 10)

Eliminate parentheses
on the right side: 5M - 16 = 3M + 30

Subtract 3M
from each side: 2M - 16 = 30

Add 16 to each side: 2M = 46

Divide each side by 2 : M = 23