If someone could explain by step that would be really

area = L x W

144 = 9 x X

144/9 = 16

 so rectangle is 9 x 16

diagonal = Square root of 9^2 + 16^2

squareroot( 81 + 256) = sqrt(337) = 18.357 = 18.36 feet

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option