I replaced a square window with a retangular one the new window is 3ft wider and 2ft higher than the square one it has an area of 42ft how long was the side of the original square window

Square window has legnth=width=x

new one is

(x+3) (x+2) = 42

x^2+3x+2x+6=42

x^2+5x+6=42

x^2+5x-36=0

factor

what multiplies to - 36 and adds to 5

-4 and 9

(x-4) (x+9) = 0

set each to zero

x-4=0

x=4

x+9=0

x=-9

false, you can't have a negative width

x=4

it was orignally 4ft long

The lines of the square window before were 4ft by 4ft