Question

6x^2+13x-5 plz help!

Answer 1

Multiply the first coefficient and the last number 6 and -5 to get 6*(-5) = -30

Now find two numbers that multiply to -30 and add to 13 at the same time.

Answer 2

well 5 times 6 = 30

Answer 3

but idk how to add it up and = 13

Answer 4

but 5+6 = 11, so that's out

Answer 5

what else multiplies to 30?

Answer 6

other than 5 and 6

Answer 7

hmm 15 times 2

Answer 8

3 times 10

Answer 9

good, so which one is negative?

Answer 10

your first choice of 15 and 2 is the right one (sort of), but one of them is negative

Answer 11

o hmm -2?

Answer 12

good

Answer 13

so 15 and -2

Answer 14

= -30

Answer 15

now when u add them both together u get -13 right?

Answer 16

more like +13, but you have the right idea

Answer 17

o my bad yea so it would be (x+15)(x-2)?

Answer 18

not quite

Answer 19

ooohh

Answer 20

because that first coefficient is NOT 1, we can't use the trick I showed you before

Answer 21

but the two numbers we just found are still important

Answer 22

oook so what should i do now?

Answer 23

break up 13x into 15x - 2x to get


6x^2+15x - 2x -5


Then factor this by grouping

Answer 24

Do you know how to do that ?

Answer 25

hmmm not really can u show me?

Answer 26

6x^2+15x - 2x -5


(6x^2+15x) + (-2x -5) .... pair off the terms in parenthesis


3x(2x+5) - 1(2x + 5) ... factor out 3x from the first group and -1 from the second


(3x - 1)(2x + 5) ... factor out the GCF 2x+5


So 6x^2+15x - 2x -5 factors to (3x - 1)(2x + 5)


By extension, this means 6x^2+13x-5 factors to (3x - 1)(2x + 5)

Answer 27

so would it be 6x^2+13x-5=(3x-1)(2x+5)?

Answer 28

yes

Answer 29

thank you sooo much

Answer 30

yw