(2x+3y-5)的平方怎么算啊~

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(2x+3y-5)的平方怎么算啊~

(2x+3y-5)的平方
=(2x+3y)²-10(2x+3y)+25
=4x²+12xy+9y²-20x-30y+25

(2x+3y-5)(2x+3y-5)
=2x(2x+3y-5)+3y(2x+3y-5)-5(2x+3y-5)
=4x²+6xy-10x+6xy+9y²-15y-10x-15y+25
=4x²+12xy-20x-30y+9y²+25