①(x+y)²-(3x-2y)²
=[(x+y)+(3x-2y)][(x+y)-(3x-2y)]
=(4x-y)(-2x+3y)
②9(2a+3b)²-25(3a-b)²
=[3(2a+3b)+5(3a-b)][3(2a+3b)-5(3a-b)]
=(21a+4b)(-9a+14b)
③a³+4a²b+4ab²
=a(a²+4ab+4b²)
=a(a+2b)²
如果不懂,请Hi我,祝学习愉快!
①(x+y)²-(3x-2y)²
=[(x+y)+(3x-2y)][(x+y)-(3x-2y)]
=(4x-y)(-2x+3y)
②9(2a+3b)²-25(3a-b)²
=[3(2a+3b)+5(3a-b)][3(2a+3b)-5(3a-b)]
=(21a+4b)(-9a+14b)
③a³+4a²b+4ab²
=a(a²+4ab+4b²)
=a(a+2b)²
如果不懂,请Hi我,祝学习愉快!