Question

the digit in the unit place of a two digit number is 4 times the digit in the tens place the number obtained by reversing the digits exceeds the given number by 54 find the given number do this method is linear equation in one variable

Answer 1

let the number is xy
$x =4 y \\ x -4y = 0 \: \: \: \: eq1 \\ 10y + x = 10x + y + 54 \\ x - 10x + 10y - y = 54 \\ - 9x + 9y = 54 \\ - x + y = 6 \: \: \: eq2 \\ add \: both \: eqs \\ 3y = 6 \\ y = \frac{6}{3} \\ y = 2 \\ x= 4y\\ x = (4)2 \\ x = 8\\ so \: the \: number \: is \: 28$