Question

Factor completely: −5k2 + 20k − 30

−1(5k2 − 20k + 30)

−5(k2 − 4k + 6)

−5k(k2 − 4k + 6)

−5(k2 + 4k − 6)

Answer 1

−5k^2 + 20k − 30
= -5k^2 + 4(5)k - 5(6)
What is the common factor for these three terms?

Answer 2

5 isnt it

Answer 3

5 is it

Answer 4

Yes. You can also take out one more... Can you try?

Answer 5

i think 5 is the only number that can go into all three terms other than 1 that is

Answer 6

You can also take out -1 as the common factor...
Now, take out the common factors and group the rest of the terms, can you?

Answer 7

−1(5k2 − 20k + 30) i think thats it

Answer 8

Not really. Didn't you mention 5 is also a common factor?

Answer 9

im not sure

Answer 10

−5k^2 + 20k − 30
= -5k^2 + 4(5)k - 5(6)
= -5k^2 - 4(-5)k - 5(6)
Now, can you observe what is the common factor?

Answer 11

give me a sec

Answer 12

not really still dont quite understand

Answer 13

what are the factors for the first term?