Question

合并同類(lèi)項(xiàng)：x²y-xy²+3x²y-xy²=________．

Answer 1

4x²y-2xy²
分析：先運(yùn)用交換律，先加3x²y再減xy²，然后運(yùn)用乘法分配律，進(jìn)行提取數(shù)字，解答即可．
解答：x²y-xy²+3x²y-xy²，
=x²y+3x²y-xy²-xy²，
=（1+3）x²y-（1+1）xy²，
=4x²y-2xy²；
故答案為：4x²y-2xy²．
點(diǎn)評(píng)：此題考查是運(yùn)算定律的運(yùn)用，應(yīng)理解掌握，靈活運(yùn)用．