①x2-8x-7=0②x2+14x-15=0③t2-(2/3)t-(8/9)=0④4(x+3)2-9(x-2)2=0
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/09/24 07:18:45
①x2-8x-7=0②x2+14x-15=0③t2-(2/3)t-(8/9)=0④4(x+3)2-9(x-2)2=0
①x2-8x-7=0
Δ=64+4×7=64+28=92;
x=(8±2√23)/2=4±√23;
(②x2+14x-15=0
(x+15)(x-1)=0;
x=1或x=-15;
③t2-(2/3)t-(8/9)=0
(t-4/3)(t+2/3)=0;
t=4/3或t=-2/3;
④4(x+3)2-9(x-2)2=0
4(x+3)²=9(x-2)²;
2(x+3)=±3(x-2);
2x+6=3x-2或2x+6=-3x+2;
x=8或x=-4/5;
Δ=64+4×7=64+28=92;
x=(8±2√23)/2=4±√23;
(②x2+14x-15=0
(x+15)(x-1)=0;
x=1或x=-15;
③t2-(2/3)t-(8/9)=0
(t-4/3)(t+2/3)=0;
t=4/3或t=-2/3;
④4(x+3)2-9(x-2)2=0
4(x+3)²=9(x-2)²;
2(x+3)=±3(x-2);
2x+6=3x-2或2x+6=-3x+2;
x=8或x=-4/5;
已知方程x2+y2-2(t+3)x+2(1-4t2)y+16t2+9=0(t属于R)的图形是圆
已知方程x2+y2-2(t+3)x+2(1-4t2)y+16t4+9=0
用配方法解下列方程①x2-2x-2=0②x2+8x-9=0③2x2+1=-3x④3x2-6x+4=0
已知集合M={x|x2-2x>0},N={x|x2-4x+3
(x2+x)2-4(x2+x)-12=0
x2+﹙1/6﹚x-1/3=0②x2-2x=3③x2-4x-2=0④-2x²-x+7=0⑤3x²-x
解方程:1/x2+x +1/x2+3x+2 +1/x2+5x+6 +1/x2+7x+12 +1/x2+9x+20=5/x
x(2x-1)2-4(x-3)(x2+3x+9)-(9+2x)(9-2x)=0
已知方程x2+y2-2(t+3)x+2(1-4t2)y+16t4+9=0表示一个圆.
已知5x2-3x-5=0,则5x2-2x-15x
①2x2-6x+1=0②3x2+8x-1=0③2x2-3x=2④3x2=-6x+8⑤2x2-7x+2的最小值⑥-3x
观察下列方程:①x2-2x-2=0;②2x2+4x-1=0;③2x2-4x+1=0;④x2+6x+3=0.上面四个方程中