如果方程组2X 3Y=K-1
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![如果方程组2X 3Y=K-1](/uploads/image/f/3698114-50-4.jpg?t=%E5%A6%82%E6%9E%9C%E6%96%B9%E7%A8%8B%E7%BB%842X+3Y%3DK-1)
k=-1b=2
{3X+2y=K+1{4X+3y=K-1的解适合于X>Yx=k+5y=-k-7x>yk+5>-k-72k>-12k>-6k=-1,-2,-3,-4,-5
1.3x+y=k……(1)x+3y=2………(2)(1)+(2),得:4x+4y=k+24(x+y)=k+2x+y=(k+2)/4根据题意(k+2)/4<2k+2<8k<62.设小朋友有x人,则苹果有
解出x=(7k-4)/5y=(-8k+11)/5由x>yk>1
1.解方程组得X=7K/5+1>0Y=-3K/5-1
2x+3y=k-1(1)3x+2y=3k+1(2)(1)+(2)5x+5y=4kx+y=4k/53x+3y=12k/5(3)(3)-(1)x=7k/5+1>0k>-5/7(3)-(2)y=-3k/5-
3x+y=k①x+3y=2②②乘以3,得3x+9y=6③③减去①,得8y=6-ky=(6-k)/8将y=(6-k)/8代入②中,得x+3(6-k)/8=2x=2-3(6-k)/8因为x,y
2k+2b=-62k+b=-1>>>>>>>>>>>b=-5,>>>>>>>>>>>>k=2再问:我也是这么解的,可你看看此题:一次函数Y=KX+B的图象经过点(2-1)和(03),那么这个一次函数的
2x+y=3k+1x+2y=3-2k相加3x+3y=4+kx+y=5则3x+3y=15所以4+k=15k=11
如果方程组{2x+3y=k-1;3x+2y=3k+1的解满足x>y,则k为多少?2x+3y=k-1.(1)3x+2y=3k+1.(2)(2)-(1)得x-y=2k+2,故有2x-2y=4k+4.(3)
原式=4x29y2•27y364x3•4xy=34x2.故答案为34x2.
k=-6求方程组得:x=k+5,y=-k-7由x
3X+2Y=K+1------------------①4X+3Y=K-1------------------②②-①得X+Y=-2----------------------③由①得X+2(X+Y)
(2x4-4x3y-x2y2)-2(x4-2x3y-y3)+x2y2=2x4-4x3y-x2y2-2x4+4x3y+2y3+x2y2=2y3,因为化简的结果中不含x,所以原式的值与x值无关.
(1)×3-(2)×2得x=k+5把x=k+5代入(1)得3k+15+2y=k+1∴y=-k-7根据题意得k+5
(1)k=5/8①*5-②得12k=-4k+10k=5/10(2)a=-12ax+4y=1212x-4y=4(12+a)x=16当a=-12时方程无实数解(3)3x+5y=m+2①2x+3y=m②②*
4x-3y=7,[(k+1)/2]x-y=k-3.8x-6y=14,3(k+1)x-6y=6k-18.二式减一式等于:(3k-5)x=6k-32,x=(6k-32)/(3k-5)有得:y=(3k-27
2k+b=1①-k+b=-3②①-②3k=4k=4/3把k=4/3代入①中得8/3+b=1b=1-8/3b=-5/3所以方程组的解为k=4/3,b=-5/3
x+2y=2k(1)3x+7y=k-1(2)(1)×10-(2)×310x+20y-9x-21y=20k-3k+3x-y=17k+3x与y的差是37x-y=37所以17k+3=37k=2
2x+3y=-k+2,①3x-2y=5k+3②2*①+3*②13x=13k+13所以x=k+1代入①y=-kx-y=2k+1=5k=2