Question

A number between 10 and 100 is 8 times the sum of its digits. If 45 is substracted
from it, the result equals the number formed by interchanging its digit. Find the
number

Answer 1

Answer:

72

Step-by-step explanation:

Let the number be $xy$

Value of number = $10x+y$

$10x+y=8(x+y)$

$10x+y=8x+8y$

$2x-7y+0........(1)$

$10x+y-45=10y+x$

$9x-9y=45$

$x-y=5............(2)$

Multiply by $-2$

$-2x+2y=-10$

Add to $(1)$

$-5y=-10$

$y=2$

$x-y=5$

$x-(2)=5$

$x=7$

Number = 72

hope this helps...