In a two-digit number, the tens digit is two less than the units digit. if the digits are reversed, the sum of the reversed number and the original number is 154. find the original number.

Denote the number by , where are positive integers between 0 and 9 .

"the tens digit is two less than the units digit"

Reversing digits gives a new number .

"sum of the reversed number and the original number is 154"

Simplify the second equation:

Since , by substitution we get

which in turn gives

So the original number is .

it is probably the graph on the bottom right.

the correct answer is c