Question

the width of a rectangular picture is 7 in less than the length. the area of the picture is 98in 2 what is the length and width of the picture

Answer 1

here's the first equation:
w = l - 7
Knowing this:
l*w = 98
Input w:
l*(l - 7) = 98
l^2 - 7l - 98 = 0
Factor:
(l-14)(l+7) = 0
Length can't be a negative number, -7 is rejected
The length is 14, the width is 7