Question

2x² -7x += 15
Help Please

Answer 1

Do you use the quadratic formula

Answer 2

2x^2 - 7x += 15 means 2x^2 - 7x = 2x^2 - 7x + 15

Answer 3

is it += or just =

Answer 4

I see. it is =.

Answer 5

no I don't use any formula

Answer 6

Im confused what

Answer 7

in your original post, you have typed 2x² -7x "+=" 15 .

Answer 8

Oh woops

Answer 9

that is why I said that

Answer 10

its suppose to be 2x² -7x = 15

Answer 11

sorry

Answer 12

2x² -7x -15= 0
2x^2 + (10x - 3x) -15=0
(2x^2 + 10x) - (3x +15)=0
2x(x + 5) -3 (x +5)=0
(2x-3)(x+5)=0

Answer 13

So you use factoring

Answer 14

sorry. I made a mistake there

Answer 15

2x² -7x -15= 0
2x^2 + (-10x + 3x) -15=0
(2x^2 - 10x) + (-3x +15)=0
2x(x - 5) -3 (x -5)=0
(2x+3)(x-5)=0

Answer 16

hold on im solving it all over again

Answer 17

yeah. I messed it:)

Answer 18

I got (x-5)(2x +3) so the same thing

Answer 19

you need to make -7x into 2 parts so that you can pull out common factors like I did before

Answer 20

then you set them both to zero and solve right?

Answer 21

yes. that's right.

Answer 22

and do you know why?

Answer 23

Would you have to check the answers since its a radical equation

Answer 24

Yeah I know why because to solve for y you must plug in 0 for x

Answer 25

I mean to solve for x you plug in 0 for y

Answer 26

because. in order to be 0 of a multiplication of 2 terms happens only when one of them is equal to zero.
so we argue that
if (x-5)(2x +3) =0
(x-5) or (2x+3) has to be zero

Answer 27

Oh yeah and that but would you ahve to check your answer since its a radical equation

Answer 28

are you still here?

Answer 29

2x² -7x -15= 0
2x^2 + (-10x + 3x) -15=0
(2x^2 - 10x) + (3x -15)=0
2x(x - 5) +3 (x -5)=0
(2x+3)(x-5)=0

Answer 30

today is a bad day:D