Question 272641
the tens digit of a two digit number is 5 more than the units digit. five times the units digit is 1 less than twice the tens digit. find the number

Let the number be xy

X=y+5

5y=2x-1

Re write these eequations 

   x-y =5------------1
 -2x+5y = -1---------2

Multiply equation 1 by 2 and add it to equation 2

2x-2y=10

+3y =9

y=9/3
y=3

So x=8
The number is 83