\(\left(3x-2y\right)^2\)
\(=9x^2-2.3x.2y+4y^2\)
\(=9x^2-12xy+4y^2\)
\(\left(3x+4\right)\left(5x-2\right)\)
\(=3x.5x+3x.\left(-2\right)+4.5x+4.\left(-2\right)\)
\(=10x^2+14x-8\)
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a,(3x-2y)2
=(3x)2-2*3x*2y+(2y)2
=9x2-12xy+4y2
b,(3x+4)(5x-2)
=15x2-6x+20x-8
=15x2+14x-8
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