Question

factor: x^2-6x-9y^2+9

Answer 1

\[x^2-6x-9y^2+9\]

Answer 2

would grouping work here?

Answer 3

hint: Factor x^2-6x-9y^2 and ignore the 9 at the very end

Answer 4

btw, i think it should be x^2-6xy-9y^2+9

Answer 5

i cant factor x^2-6x-9y^2 because they are two different variables

Answer 6

that's why I was thinking there was a typo and it should be x^2-6xy-9y^2

Answer 7

nope that's not it, i copied the question right
:S

Answer 8

oh i see what to do, one sec

Answer 9

x^2-6x-9y^2+9

x^2-6x+9-9y^2

(x^2-6x+9)-9y^2

Do you see where to go from here?

Answer 10

i dont understand why you did that

Answer 11

x^2-6x+9-9y^2

Answer 12

factor x^2-6x+9

what do you get?

Answer 13

why do we ignore the 'y' value ?

Answer 14

just focus on this for now, you'll see later

Answer 15

alright, so it would be x^2-3x-3x+9

Answer 16

good, keep going

Answer 17

(x-3)^2

Answer 18

so

x^2-6x-9y^2+9

x^2-6x+9-9y^2

(x^2-6x+9)-9y^2

(x-3)^2 - 9y^2

see what to do now?

Answer 19

mhmm, thank you very much !

Answer 20

that's great

Answer 21

@burhan101

Do you recognize this expression as the difference of squares?

(x-3)^2 - 9y^2