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

I need help because I have tried all the answers as this a multiple choice question.

a)
(x+4)(x-9)
(4+4)(-9-9)
(8)(-18)
-144
b)
(x+4)(x-9)
(4+4)(9-9)
(8)(0)
0
c)
(x+4)(x-9)
(-4+4)(9-9)
(-8)(0)
0
d)
(x+4)(x-9)
(-4+4)(-9-9)
(0)(-18)
0

1 answer

The whole setup is bogus

I'd go with (c), since it correctly notes that the solutions are -4 and 9.

But -4+4 is (0), not (-8)

If this is a proposed way to solve for zeroes, it's really stupid. x cannot be both -4 and 9 at the same time.

Run far, run fast from this course!!!