Question

Solve 5x2 = –45x.

Answer 1

1. Move 45x to the left side by adding 45x to both sides.

Answer 2

I did that but i dont know what to do next

Answer 3

What do you have?

Answer 4

5x2+45x

Answer 5

Don't forget "= 0". This is an equation.
2. Factor a common factor out of left side. What is the largest factor you can factor out of 5x^2 and 45x?

Answer 6

9 and 5

Answer 7

That's correct for the number part. What about the variable part?
5x^2 = 5*x*x
45x = 3*3*5*x
Which factors do 5x^2 and 45x have in common?

Answer 8

a+b=5 and a*b=45 so that cant be right

Answer 9

Follow along, don't jump ahead. We'll get there very soon.

Answer 10

okay lead the way

Answer 11

We are here now:
5x^2 + 45x = 0

What do 5x^2 and 45x have in common. See below:
5x^2 = 5*x*x
45x = 3*3*5*x
Which factors do 5x^2 and 45x have in common?

Answer 12

yup