I think it's D because you times everything from the left column to the right column
Domain is all real numbers.
Range is all real numbers such that y is greater than -49/12
x = 12 , y = 18 (12, 18) is the solution, intersection of the two lines.
If alonzo is x then the equation is
x + (x +3) + 2(x + 3) = 57
Which equals
x + x + 3 + 2x + 6 = 57
4x + 9 = 57
4x = 48
x = 12
This means alonzo is 12 years old and alexis is 3 years older so alexis is 15 years old
Answer = 15 years old