Question

the sum of the digit of a two digit number is 7 if the digits are reversed the new number increased by 3 equal to 4 times the original number find the original number

Answer 1

let the original number be xy

x+y=7

After reversing the number formed =yx

10y+x+3=4(10x+y)

on solving we get the number 16.

10y+x+3=40x+4y

6y-39x=-3