Paulroshomesviz
Answered

17. The units digit of a two-digit number is five more than the tens digit. If the units digit is added to the number with its digits reversed, the result is 79. Find the number.

Sagot :

Jeremiaviz
Let x be the units digit of the number and y be the the tens digit.
x = y + 5
x - y = 5

x + ( 10x + y) = 79
x + 10x + y = 79
11x + y = 79

11 (x- y = 5)
(subtract from the first equation)
      11x - 11y =55
-     11x + y =  79
         0 - 12y = -24
         -12y = -24
         -12y / -12 = -24/-12
            y = 2

x - y = 5
x - 2 = 5
x = 5 + 2
x = 7

The number is 27.