Question

what is the number which is 9 times the sum of its two digits ?​

Answer 1

Answer:

Let the unit digit be x

tens digit be y

The two digit number =10x+y

According to the given statement, the information can be written in the form of linear equation

ie, 10x+y= 9(x+y)

10x+y= 9x+9y

10x-9x+y-9y=0

x-8y =0