2x- 3y 1 =0

y1=y2可得：2x平方-3x+1=4x平方+4x+7移项并合并同类项得：2x平方+7x+6=0分解因式得（x=2)(2x+3)=0可得x1=-2;x2=-3/2所以可知x=-2或-3/2时,y1=y

设y1=k1x^2,y2=k2/(x+3)y=y1-y2=k1x^2-k2/(x+3)因为-k2/3=2k2=-69k1+6/6=0k1=-1/9因此y=-x^2/9+6/(x+3),x不等于-3

由{y=1/2x-2{y=-x+1可得1/2x-2=-x+1即x=2则y=-1所以{y=1/2x-2{y=-x+1的解是{x=2{y=-1画图后可看出:当x＞2时,y1>y2当x＜2时,y1

1)由题意有a^3x+1=a^（-2）x化简有(a^（-2）-a^3）x=1∵a＞0且a≠1,∴a^（-2）-a^3≠0∴当x=1/(a^（-2）-a^3)时,y1=y22)由题意,a^3x+1＞a^

设y1=k1xy2=k2/xy=y1+y2=k1x+k2/x将x=1时y=0与x=2时y=3带入此式则2k1+k2/2=3解方程组求k1和k2解得k1=2k2=-2k1+k2=0所以y与x的关系就是y

解析：∵y1与x²成正比,y2与x+3成反比例,∴设y1=k1x^2,y2=k2/(x+3)∴y=y1+y2=k1x^2+k2/(x+3)由当x=0时,y=2；当x=3时,y=0,∴k2/3

1、OA=t,OB=8/t,AC=k/t,BD=k*t/8四边形ODPC的面积=t*8/t-1/2*t*k/t-1/2*8/t*k*t/8=68-k=6k=2；2、k=3时,S有最大值；3、t>4时,

y1=y2=>a^(x^2-2x+3)=a^(2x^2+4x+3)=>x^2-2x+3=2x^2+4x+3=>x=0,x=-6------------------------------y1>y2=>

y1=y2-2/3x+1=x2/3x+x=15/3x=1x=3/5y1=y2-5-2/3x+1=x-52/3x+x=1+55/3x=6x=18/5

y1=x²-x+3,y2=√3（2x-1）若y1=y2则x²-x+3=√3(2x-1)移项：x²-(1+2√3)x+（√3+1)√3=0(x-√3)[x-(1+√3)]=

设Y1=k1xY2=k2xY=Y1+Y2=k1x+k2/x当X=1.Y=-3时...k1+k2=-3把XY代进去当X=2,Y=0时2k1+k2/2=0也就是4k1+k2=0所以k1=1k2=-4所以Y

由y1-y2=x^2-2x-3=(x-3)(x+1),得1)当x>3orxy22)当-1

把z=[y1y2]改成z=[y1;y2].因为y1、y2都是行向量,拼接成矩阵时应该放在不同行里.

由题意：令y1=k1*(x+1),y2=k2/(x+1)那么y=k1(x+1)+k2/(x+1)由题意：k1+k2=33k1+k2/3=7解得：k2=9/4,k2=3/4所以解析式为：y=9(x+1)

由题意得y2=x-2将x=-3代入得y2=-54=y1+y1y2得y1=-1将x=3代入得y2=1y=-1+-1=-2

解由当x=2时,y1+y2=-1得2k1+2k2=-1即k1+k2=-1/2.①当x=3时,y1-y2=12得3k1-3k2=12即k1-k2=4.②由（1）与（2）联立解得k1=7/4,k2=-9/

1.y1=y2:-x+2=3x+4=>4x=-2=>x=-1/2y1-1/2y1>y2:-x+2>3x+4=>xx=1y=1带入y=ax+7=>a=-6

x-2=3(2x-3)x-2=6x-96x-x=-2+95x=7x=1.4

因为底数大于0且小于1,所以指数越大,则结果越小,这样就知道x^2-3x+1>x^2+2x-5解得x

y1=y22x+1=5x+16-3x=15x=-5y1>y22x+1>5x+16-3x>15x>-5y1