Question

A number of two digits is such that twice the ten digits is 8 less than seven times the unit digit. When the digits are reversed, the number is decreased by 9. What is the number?

Answer 1

let the tens digit be x, and the unit digit be y
So the number is 10x + y,
the number reversed is 10y + x

10x+y - (10y+x) = 9
9x - 9y = 9
x - y = 1 or x = y+1 **

2x = 7y-8
sub in **
2(y+1) = 7y - 8
2y + 2 = 7y - 8
-5y = -10
y = 2

The number is 32

check:
the number reversed is 23, which is 9 less than 32.
Twice the ten digit is 6
7 times the unit digit = 14, which is 8 less than 6
My answer is correct.

Answer 2

Pls how did you get 32 as the number

Answer 3

Superb

Answer 4

Thanks,but why is it 10x+y and not x+y