Question

How do you solve 5x² - 20x² (GCF)

Answer 1

GCF means?

Answer 2

-15x^2

Answer 3

GCF means Greatest Common Factor.

Answer 4

Am I right?

Answer 5

@allea_marie reply pls

Answer 6

Hello?

Answer 7

There needs to be more here, for there to be something to solve.

Answer 8

Yes it stands for Greatest Common Factor

Answer 9

so what are the two numbers that you want to find the greatest common factor of?

Answer 10

But why do you need GCF to solve this? It is quite simple. Just subtract 5-20 and carry over the x^2. That would be -15x^2

Answer 11

Okay thanks, how would you solve 2x² - 21x=54

Answer 12

that one can be solved by factorising the polynomial.

Answer 13

\[ 2x^2 - 21x =54 \]
\[2x^2 - 21x - 54 = 0 \]
Now you want to solve:
\[(2x + a)(x +b) = 2x^2 - 21x - 54 \]
Note that you must have \[ a*b = -54 \]

Answer 14

this won't always work so easily. But I can see here that it does.

Answer 15

Okay thank you