You can put this solution on YOUR website!
Let the two digit = 10x + y
Write an equation for each statement
"The sum of the digits of a two-digit number is 9."
x + y = 9
y = (9-x); use this for substitution
" If the number is doubled, then decreased by 36, the answer is the original number with the digits reversed."
2(10x+y) - 36 = 10y + x
20x = 2y - 36 = 10y + x
20x - x = 10y - 2y + 36
19x = 8y + 36
Find the number.
Replace y with (9-x) in the above equation, find x:
19x = 8(9-x) + 36
19x = 72 - 8x + 36
19x + 8x = 72 + 36
27x = 108
x = 4:
I'll let you find y, check solution in the given statement