Question

Multiply: (x – 4)(x + 5)

(a) x2 + 5x - 20,

(b) x2 - 4x - 20,

(c) x2 - x - 20,

(d) x2 + x - 20.​

Answer 1

$\huge\underline\mathfrak{\pink{Solution }}$

(x – 4)(x + 5).

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

= x2 + 5x – 4x – 20.

= x2 + x - 20.

Answer: (d)

Answer 2

Answer:

➡First, outer, Inner, Last

(x+4)(x-5)

do the first in both groups- x(x), then the outer in both groups (the first x and five) x(-5), then the inner in both groups (4 and the second x) 4(x), then the last in both groups (4)(-5)

so you would get x(x)+x(-5)+4(x)+4(-5)

combined it is x^2-5x+4x-20 or x^2-x-20

***Make sure that when there is a subtraction in the problem, like this one, you treat it as a negative number. If you keep it as x+(-5) it will help you when you are figuring out what the correct signs .....

The correct option is c....

please mark as brainliest....