y=﹣2x²+4x+1解方程
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2x+y=4x-y-1/22x-2y-1/2=08x-8y-4=01式4x-y-1/2=10+6x+2y/42x+6y/4+21/2=08x+6y+42=02式2式-1式得到:8x+6y+42-8x+
(3X+2Y)/4=(2X+3Y)/5①(3X+2Y)/4=(X-1)/6②化简①,4(2X+3Y)=5(3X+2Y),8X+12Y=15X+10Y,2Y=7X,Y=7X/2③化简②4(X-1)=6(
(3x+2y)/4=(2x+y)/55*(3x+2y)=4*(2x+y)15x+10y=8x+4y7x=-6yx=-6/7y(2x+y)/5=(x-y+1)/66*(2x+y)=5*(x-y+1)12
8x+5y=9(1)3x-5y=1(2)(1)+(2)11x=10x=10/11y=19/553x-2y=5(1)5x+4y=12(2)(1)*26x-4y=10(3)(2)+(3)11x=22x=2
x=1,y=2或x=2,y=3
X=1+2Y3(1+2y)-4y=03+6y-4y=02y=-3y=-1.5x-2*(-1.5)=1x+3=1x=-2答案X=-2Y=-1.5
2(1-x)=2x2-2x=2x2=2x+2x4x=2x=1/24分之3y-1=74分之3y=8y=8除以4分之3y=3分之324分之(y+2)-6分之2-3=04分之(y+2)=6分之2+34分之(
对于第一个问题,答案是X=68y=64对于第二个问题,答案是x=三分之一y=0
因为y=-2x所以x^2+(-2x)^2=0解得x=正负√5/5所以y=正负2√5/5所以当x=√5/5,y=-2√5/5当x=-√5/5,y=2√5/5尽微薄之力,
(x-y)^2=9,(x+2y)^2+(x+2y)=2,2x-1/y=3[2xy-1=3y],x=2y[4y^2-3y-1=0,y=1或者y=-1/4],x=2或者x=-1/2
解1:(x+y)-(x+y)^2=(x+y)(1-x-y)解2:2x²=3x2x²-3x=0x(2x-3)=0x1=0,x2=3/2解3:(3x-1)²-4=0(3x-1
化简x+y=105x+7y=625x+5y+2y=622y=62-50y=6x=4
x-4y=-1…………①2x+y=16…………②①+②×4得9x=63x=7把x=7带入①得7-4y=-14y=7+14y=8y=2∴x=7,y=2
化简第二个方程得:x=4y③将③带入①得:5y=60解得y=12将y=12带入①得x=48
两边乘128x-8y-3x-3y=-125x-11y=-126x+6y-8x+4y=16x-5y=-4x=5y-4代入5x-11y=-1225y-20-11y=-1214y=8y=4/7x=5y-4=
2(x-y)/3-(x+y)/4=-13(x+y)-6(x-y)=6一式去分母得8(x-y)-3(x+y)=-12二式除3得(x+y)-2(x-y)=2设x+y为a,x-y为b代入原式8b-3a=-1
两个未知数,只有一个方程,怎么解?这是一个圆方程:由y/(x+2)×y/(x-4)=-1y²=-(x+2)(x-4)y²=-x²+2x-1+9y²=-(x-1)
(3x+2y)/4=x+1/3y得x=2/3y(3x+2y)/4=3(x-2)+y得9x+2y-24=0故y=3,x=2
2x+y=2(1)-x+y=5(2)3x=-3x=-1y=4