Solve (3x-2y)^2?

Question

I know what the answer is. 9x^2 + 4y^2 - 12xy. I just can't figure out how to get there.

Thanks

Answer 1

(3x - 2y)² =

(3x - 2y)(3x - 2y) =

9x² - 6xy - 6xy + 4y² =

Collect like terms

9x² - 12xy + 4y²

- - - - - - - - s-

Answer 2

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RE:
Solve (3x-2y)^2?
I know what the answer is. 9x^2 + 4y^2 - 12xy. I just can't figure out how to get there.

Thanks

Answer 3

(3x-2y)^2

= (3x-2y)(3x-2y)

"FOIL" method--->
First: (9x^2) ------>which came from (3x)*(3x)
Outside: (-6xy) ----->which came from (3x)*(-2y)
Inside: (-6xy) ----> which came from (-2y)*(3x)
Last: (4y^2) ----> which came from (-2y)*(-2y)

So putting those together - ADD together the like components (xy's in this case):
(9x^2 - 6xy - 6xy + 4y^2)
= 9x^2 -12xy + 4y^2


PS There is also an identity you can memorize. But the FOIL method works too. Whichever way is easier for you.
It's a trick to help speed up your exam time if you use it.
(a+b)^2 = a^2 + 2ab + b^2
(3x-2y)^2 = 9x^2 + 2(-6xy) + 4y^2
= 9x^2 - 12xy + 4y^2.

Answer 4

This Site Might Help You.

RE:
Solve (3x-2y)^2?
I know what the answer is. 9x^2 + 4y^2 - 12xy. I just can't figure out how to get there.

Thanks

Answer 5

Try as given by the one above me.or tyr remebering the identity that:
(a+b)^2=a^2+b^2+2a.b
so (3x-2y)^2=9x^2+4y^2-12xy
hope it helps

Answer 6

solve 3x 2y 2: https://tinyurl.im/e/solve-3x-2y-2

Answer 7

the basic formula is:
(a+b)^2=a^2+2ab+b^2
In your case it's:
(3x)^2 +2×(3x)×(-2y)+(-2y)^2
which equals:
9x^2-12xy+4y^2

Answer 8

(3x-2y)^2
=(3x)^2-2(3x)(2y)+(2y)^2
=9x^2-12xy+4y^2

Answer 9

(3x-2y)^2= (3x-2y)(3x-2y)
use the foil method (something like this)
(3x)(3x) = 9x^2
(-2y)(3x) = -6xy
(3x)(-2y) = -6xy
(-2y)(-2y) = 4y^2
add them all together
9x^2+4y^2-12xy

Answer 10

If u have (a-b)^2=(a*a)+(b*b)-(2*a*b) so
(3x-2y)^2=(3x*3x)+(2y*2y)-(2*3x*2y)
=9x^2+4y^2-12xy