问题
解答题
已知A=8x2y-6xy2-3xy,B=7xy2-2xy+5x2y,求3B-2A.
答案
∵A=8x2y-6xy2-3xy,B=7xy2-2xy+5x2y,
∴3B-2A
=3(7xy2-2xy+5x2y)-2(8x2y-6xy2-3xy)
=21xy2-6xy+15x2y-16x2y+12xy2+6xy
=33xy2+27x2y.
已知A=8x2y-6xy2-3xy,B=7xy2-2xy+5x2y,求3B-2A.
∵A=8x2y-6xy2-3xy,B=7xy2-2xy+5x2y,
∴3B-2A
=3(7xy2-2xy+5x2y)-2(8x2y-6xy2-3xy)
=21xy2-6xy+15x2y-16x2y+12xy2+6xy
=33xy2+27x2y.