Question

Multiply (5x^2+x-4)(x+2)
A.5x^3+x^2-4x-8
B.5x^3+11x^2-2x-8
C.5x^3+10x^2-4x-8
D.5x^3+20x^2+2x-8

Answer 1

i dont understand how to foil this prob with the three numbers in the first part of the equation

Answer 2

(5x^2+x-4)(x+2)
(5x^2)(x) + (5x^2)(2) will be the product of 5x^2. Do you see the pattern here? It works the same for the other two numbers.

Answer 3

not really how is (5x^2)(x)+(5x^2)(2) the product of 5x^2

Answer 4

Because of (x+2). You cannot multiply (x+2) with 5x^2 at once, so you have to separate x and 2.
Sorry, I had to say product of 5x^2 and (x+2).

Answer 5

im very confused????

Answer 6

Umm.. Okay.
Do you know how to solve
5(x+2) ?

Answer 7

5x+10

Answer 8

How about 5x^2(x+2)?
Use the same method that you used for solving 5(x+2).

Answer 9

5x^2+100?

Answer 10

5x^2 * x = 5x^3
5x^2 * 2 = 10x^2
Do you see why?

Answer 11

yeaah bcuz the x turns the ^2to ^3 and 5 times 2 equals 10

Answer 12

Right??

Answer 13

Yup! :)

Answer 14

Now you can the same thing for x and -4.

Answer 15

so 5x^2 times x would be 5x^3 and -20x^2 correct???

Answer 16

The answer is correct. :D
But I was talking about 'x' and '-4' of (5x^2+x-4).