6. Multiply: (x – 4)(x + 5)

(a) x2 + 5x - 20,

(b) x2 - 4x - 20,

(c) x2 - x - 20,

(d) x2 + x - 20.

Solution:

(x – 4)(x + 5).

= x(x + 5) -4(x + 5).

= x2 + 5x – 4x – 20.

= x2 + x - 20.

Answer: (d)

if im wrong then hope help me out