This is an odd problem. The length and width look like they should be interchanged. Anyway I'll solve it and we'll talk about the results. (x +7) (x + 3) = 396 x^2 + 7x + 3x + 21 = 396 x^2 + 10x + 21 = 396 Subtract 21 from both sides. x^2 + 10x = 396 - 21 x^2 + 10x = 375 x^2 + 10x - 375 = 0 This probably factors. (x + 25)(x - 15) x + 25 = 0 x = - 25 which makes no sense. Negatives do not describe room dimensions. x - 15= 0 x = 15. this is fine.
x+3 = 15 + 3 = 18 x + 7 = 15 + 7= 22
Check ===== Area = L * W = 18 * 22 = 496. It does check. 22 should be the length
