solve..expand whatever can someone please just show me how to get to the final product and why you did what you did to get to the final product...i don't understand where the -12xy is coming from becasue i got (9x)sq - (4y)sq...thanks everyone for the help
omg thanks a bunch KP i forgot about foil.....im refreashing myself for a college placement exam and i haven't done math in years
refreshing
8 Answers
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Since (3x - 2y)² yields the perfect square trinomial, we use this formula..
(a - b)² = a² - 2ab + b²
Hence, we have..
(3x - 2y) = (3x)² - 2(3x)(2y) + (2y)²
= 9x² - 12xy + 4y²
I hope this helps!
Source(s): Knowledge -
(3x-2y)^2 is the same as (3x-2y)(3x-2y)
FOIL >> 9x^2 - 12xy + 4y^2
another quick way to do it would be to take (3x-2y)^2
square the first term 9x^2
multiply the first term by the second term and then multiply that by 2, -12xy
square the second term, 4y^2
so you end up with the same answer as the FOIL method, 9x^2 -12xy +4y^2
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(a-b)^2 = a^2 - 2ab + b^2
(3x - 2y)^2 = 9x^2 - 12xy + 4y^2
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(just an attempt)
Eerything im the brackets will be squared
So,
9x-4y
Im not sure if you leave it at that or if it then becomes 5xy but i think you leave it as 9x-4y. I really hope i helped lol
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Solve what? That's not an equation. If you want me to expand it...
(3x - 2y)²
(3x)² + 2(3x)(-2y) + (-2y)²
9x² - 12xy + 4y²
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(A-b)sq =a^2-2ab+b^2
So 3x-2y sq
=9x^2-12xy+4y^2
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expand it become (3x -2y) (3x-2y) then, become 3x in the first bracket times 3x in the second bracket so, it becomes 9x square. then the 3x in the first bracket times with the -2y in the second bracket. so it becomes -6xy. so, 9x square -6xy. then, the -2y in the first bracket times with the 3x in the second bracket and becomes -6xy. so far, it becomes 9x square -6xy -6xy. then, the -2y in the first bracket times with the -2y in the second bracket and becomes +4y square. so, combined, then becomes, 9x square-6xy-6xy+4ysquare. then, simplify becomes 9x square-12xy+4ysquare
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( 3x - 2y ) ( 3x - 2y )
9 x ² - 6 xy - 6 xy + 4 y ²
9 x ² - 12 xy + 4 y ²