Question

the sum of the digits of a two-digit number is 7 the number obtained by interchanging the digits exceeds the original number by 27 find the numbers

Answer 1

let the digits first be x and second be y
x+y=7
and
10y+x-10x-y=27
9y-9x=27
y-x=3(put y=7-x)
7-x-x=3
-2x=-4
x=2
now put this in previous equation
x+y=7
2+y=7
y=5

Orignel Number is 10x+y
10*2+5
20+5
25

Answer 2

Answer is here. Hope it helps