the units of a number is 4 more than the tens digit. If the digits are reversed the new number is 1 less than twice the original number. Use a system of equations and substitution to find the number.

Question

I'm stuck?!?!

Answer 1

Let x be the units digit and y be the tens digit.

"The units of a number is 4 more than the tens digit"

x = y + 4

"If the digits are reversed the new number..."

The original number is x + 10y. The reversed number is 10x + y.

"...is 1 less than twice the original number."

10x + y = 1 + 2(x + 10y)