帮我出几道代数式求值的题!例：(3x-4y+2xy)-(2x-5y+5xy),其中x=-2,y=1.急用!能出几道就出几道!

+=12459gigbjf

（10x+3）×(3y+6-x),x=3,y=1
3X+Y-（0×900X）,x=5,y=3
2.5 × x × y,x=10,y=0.01
(123×2/X) + Y,x=2,y=10
1.2×（X+9）-6Y,X=1,Y=12
(78/2)*Y-5X,x=5,y=10
5xy+3X-4Y×30,X=20,Y=0.2
（3.3×X）/Y +30,X=30,Y=3
－8x2－5x(－x+3y)+(3x+2y)(x－y),其中x=2,y=－1
3ab-4ab+8ab-7ab+ab=______.a=3,b=5
7x-(5x-5y)-y=______.x=10,y=3
24a*3b-8ab=______.a=30b=0
11.(2x-3xy+4y)+(x+2xy-3y)=______.x=2,y=2
12.2a-(3a-2b+2)+(3a-4b-1)=______.a=3,b=5
13.-16x+15y-2xy=______.x=2,y=0.1
14.2x-(x+3y)-(-x-y)-(x-y)=______.x=3,y=5
16.2x+2y-[3x-2(x-y)]=______.x=0.1y=2
17.5-(1-x)-(xy-1)=______.x=3,y=11
18.( x+y)+(4xy+7x2-y2)=.x=4,y=3
19.x-2xy+4xy+y.x=12,y=3