Answer:
length x width = area
(x+7)(2x) = 520
2x2 + 14x - 520 = 0
x2 + 7x - 260 = 0
(x+20)(x-13) = 0
x = -20 (which is impossible because it creates a negative value for length and width) and x= 13
length = 20, width = 14
Step-by-step explanation:
sana makatulong
