one number is three more than four time another if the sum of the two number is 23 then find both numbers

The value of x is 19. The value of y is 4.

x = 3 + 4y

x + y = 23

Because we have a value for x we can plug it directly into the second equation.

3 + 4y + y = 23

Subtract 3 from both sides.

4y + y = 20

Combine like terms.

5y = 20

Divide both sides by 5.

y = 4

Plug this value for x back into the original equation.

x = 3 + 4 (4)

x = 3 + 16

x = 19