Asked by daisy
the sum of a two digits of a two-digit number is 10. when the digits are reversed, the new number is 36 more than the original number. find the original number.
Answers
Answered by
Reiny
let the unit digit be x and the tens digit be y
so the number is 10y + x
if we reverse the digits, the number is 10x + y
10x + y - (10y + x) = 36
9x - 9y = 36
x - y = 4
but we also know that x + y = 10
add them
2x = 14
x = 7, then y = 3
the original number was 73
check:
73-37 = 36 , all is good
so the number is 10y + x
if we reverse the digits, the number is 10x + y
10x + y - (10y + x) = 36
9x - 9y = 36
x - y = 4
but we also know that x + y = 10
add them
2x = 14
x = 7, then y = 3
the original number was 73
check:
73-37 = 36 , all is good