(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy²),其中x=-1,y=2.
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy²),其中x=-1,y=2.
先化简,后求值,
先化简,后求值,
数学人气:504 ℃时间:2020-01-28 18:07:36
优质解答
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy²)=2x²y-3xy²-3x²y+6xy²+2x²y-8xy²=x²y-5xy²=xy(x-5y)将x=-1,y=2.代入得原式=-2×(-1-10)=22
我来回答
类似推荐
猜你喜欢
- 1Betty is a girl who looks good 同义句 Betty is a ------------- ----------
- 2如图,在平面直角坐标系中,梯形ABCD的四个顶点坐标分别为A(2,4倍的根号2)、B(4,4倍的根号2)C(7,0)
- 3Would you like to go for a picnic this weekend?Let's enjoy the fresh air out
- 4怎样画三角形的的垂直平分线
- 51又9分之2的分数单位是(),它在添上()这样的分数单位就等于2他减少()个这样的分数单位就等于3分之1.
- 6There is only one goal!这句话的意思.翻译、翻译、谢谢、
- 7She ran fast to catch the early bus 改为同义句 She ran fast ()()()()catch the early bus
- 8感谢有你作文
- 9把一个圆柱体侧面积展开后,得到一个正方形,这个圆柱体底面半径是5厘米高是多少?(算式)
- 10把1.2.3.4.5.6.7.8.9几个数填到一个四位数乘以一位数等于四位数的等式中.