x=0:1:10; y=(x^3 x^2 x 2); plot(x,y);-搜答案-搜搜考试网

x-y/7-x+y/10=1/2两边乘7010x-10y-7x-7y=353x-17y=35(1)2(x-y)+5(x+y)=32x-2y+5x+5y=37x+3y=3(2)(2)*3-(1)*79y

(x+y)/6+(x-y)/10=3①(x+y)/6+(y-x)/10=-1②①可变为：(x+y)/6-（y-x)/10=3③②+③=(x+y)/3=2得x+y=6④②-③=（y-x）/5=-4得y-

3(x+y)+3(y-x)=1(1)3(x+y)+4(y-x)=-1(2)(2)-(1)得y-x=-2(3)代入（1）3（x+y)-6=1x+y=7/3=>x=7/3－y又由（3）得x=y+2y+2=

设a=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)那么y=a*(x-10);那么y^=a^*(x-10)+a*(x-10)^=a^*(x-10)+a那么y

x=4,y=0.5,x+y=4.5(与人家的做法一样……)(1)解题思路是以S3为基准,用S3表示出S1,S2,S4即可.在三角形BCD中有：S2/S3=DF/CF,故S2=(DF/CF)S3;同理,

很多数学符号,还是写出来方便.

2x-y-3=3x+2y+1=0,x=5/7,y=-11/7

4x^2+y^2-4x-6y+10=04x²-4x+1+y²-6y+9=0(2x-1)²+(y-3)²=02x-1=0y-3=0∴x=1/2y=3(2\3x根号

x-y-3绝对值+(2x+2y+10)的平方=0X-Y-3=0X-Y=32X+2Y+10=0X+Y=-5(x+y)(x-Y)=3X(-5）=-15

.死算呗xy-2x+3y-6=xy+10x-3y-30,2x-y=4xy+3x+y+3=xy+12x-2y-24,3x-y=92式减1式,x=5,y=6

①－②可得：x-y/10－y-x/10=4x-y／5＝4x-y＝20——③①＋②可得：x+y/3=2x+y=6——④由③④可得：x=13,y=－7

5(x+y)-2x=03x+5y=06x+10y=0①3x-10(x+y)=27x+10y=-2②②-①x=-2代入①y=6/5

解(x-y)(x+y)-(x-2y)²+x(3x-5y)-(x-y)(x-2y)=(x²-y²)-(x²-4xy+4y²)+(3x²-5xy

3(x+y)-4(x-y)=4(x+y)/2+(x-y)/6=1令a=x+y,b=x-y3a-4b=4(1)a/2+b/6=1则3a+b=6(2)(2)-(1)5b=2b=2/5a=(6-b)/3=2

x（x*x-1)+x(5-x*x)-6y+7=-x+5x-6y+7=2(2x-3y)+7=2*(-4)+7=-8+7=-1再问：能在写详一点吗-x+5x-6y+7再答：x（x*x-1)+x(5-x*x

y'=3-2xy'/x=1=1y'/x=0=3

4x-3y-10=08x-6y=203x-2y=09x-6y=0x=-20,y=-303x-4(x-y)=23x-4x+y=2x-y=-23x-3y=-62x-3y=1x=-7,y=-52(x+y)-

完整设1/(x+y)=a,1/(x-y)=b原方程组可变为4a+6b=39b-a=1a=9b-136b-4+6b=3b=1/6,a=1/2x+y=2x-y=6所以原方程组的解为：x=4,y=-2