Question

how can I solve -(x+5)^2 + 9 ?

Answer 1

ah! should be -(x-5)^2 + 9. I distributed the square and got x^2 + 34, but how do you factor that?

Answer 2

you made the mistake in thinking that (x-5)^2 = x^2 + 25

when in fact it should be

(x-5)^2 = x^2 - 10x + 25

Answer 3

so

-(x-5)^2 = -(x^2 - 10x + 25)

-(x-5)^2 = -x^2 + 10x - 25

Answer 4

oh! so -x^2 + 10x -16
and then you continue to factor it...

Answer 5

correct

Answer 6

(-x^2-2)+ (8x-16)
?

Answer 7

the negatives are confusing....

Answer 8

-x^2 + 10x - 16

-(x^2 - 10x + 16)

now factor x^2 - 10x + 16 and when you're done factoring, stick a negative at the front

Answer 9

whoops, should it be (x+2) (x-8), or x equals +/- 2, +/- 8 ?

Answer 10

x^2 - 10x + 16 factors to (x-2)(x-8)

so

-(x^2 - 10x + 16) factors to -(x-2)(x-8)

Answer 11

-(x^2 - 10x + 16) = 0

-(x-2)(x-8) = 0

x-2 = 0 or x -8 = 0

x = 2 or x = 8

Answer 12

you won't have the plus or minus

Answer 13

oh, ok. thank you!

Answer 14

sure thing