Question

Solve 2x 2 + x - 6 = 0
a) {-2, 3/2}
b) {-3/2, 2}
c) {}

Answer 1

this function can be factored
so the firm
(2x + a)(x + b) where a and b are 2 integers

can you factor it?

Answer 2

* to the form , i meant to say!

Answer 3

have you heard of the ac method of factoring?

Answer 4

wjat are he answers cuz i got x=2

Answer 5

its 2x^2 sorry

Answer 6

yeah i assumed that

ac method is :-

multiply first coefficient by the last which is in this case
2 * - 6 = -12

now we need to find what factors of -12 gives us the middle term in the original expression which is +1 ( from the + x

so we try 4x - 3x ( = + x0

so we have
2x^2 + x - 6 = 0
2x^2 + 4x - 3x - 6 = 0

Answer 7

* ( = +x )

Answer 8

Do you follow that OK?

Answer 9

yea

Answer 10

OK so now we factor by grouping ( groups of 2)
2x^2 + 4x - 3x - 6 = 0
2(x + 2) = -3(x + 2) = 0

Answer 11

oh sorry the second line is

2(x + 2) - 3(x + 2) = 0

Answer 12

what do you notice about what is in each parenthesis)?

Answer 13

their the same

Answer 14

right so we can take out x + 2 to give
(x + 2)(2x - 3) = 0


damn it I made another mistake in the last post its

2x(x + 2) - 3(x + 2) = 0

Answer 15

so do you know how to find x from
(2x - 3(x + 2) = 0

Answer 16

i cant really rember its been awhile sence ive done this stuff

Answer 17

ok well when to entities are multiplied together and the answer is 0 eother one of them must equal zero so we can split it up into

2x - 3 = 0 and x + 2 = 0

giving x = 3/2 from the first equation and x = what?

Answer 18

so the answer will be written in the form { ?, 3/2}

Answer 19

so would the awnser be c?

Answer 20

how can it be c? - when we know that one root is 3/2?

Answer 21

x + 2 = 0

x = ?

Answer 22

{} means there are no real roots.

Answer 23

i ment b

Answer 24

a*