Question

Solve for the roots in the following equation. Hint: Factor both quadratic expressions.

(x^4 + 5x^2 - 36)(2x^2 + 9x - 5) = 0

Answer 1

ok so Which two numbers add up to 5 and multiply to -36?

Answer 2

in the equation?

Answer 3

yes for the first part

Answer 4

ok so what is -4 plus 9?

Answer 5

five =)

Answer 6

and does those two numbers multiplies to -36?

Answer 7

indeed

Answer 8

so when we rewrite its gonna be : (x^2-4)(x^2+9)(2x^2 + 9x - 5) = 0

Answer 9

okay

Answer 10

now x^2-4 fits the form a^2 - b^2 so we are gonna write it like this
(x^2-2^2)(x^2+9)(2x^2 + 9x - 5) = 0

Answer 11

oki

Answer 12

we are gonna use difference of square so a^2-b^2=(a+b)(a-b)

Answer 13

so (x+2)(x-2)(x^2+9)(2x^2 + 9x - 5) = 0

Answer 14

Multiply 2 by -5, which is -10.
Which two numbers add up to 9 and multiply to -10?

Answer 15

what do you think?

Answer 16

dan

Answer 17

sorry ill brb my father needs help

Answer 18

k

Answer 19

hello im back

Answer 20

in the first and the last

Answer 21

so we are factoring 2x^2 + 9x - 5 right?

Answer 22

um maybe i really dont get any of this stuff

Answer 23

ok these trinomials factor to the form
(ax + b(bcx + d) whete a b c and d are integers

now we have 2x^2 + 9x - 5

so start we must have 2x in one bracket and x in the other

(2x + b)(x + d)

because the 2x 8 x will give us the 2x^2

do you follow that ok?

Answer 24

* 2x * x = 2x^2