3x²减9x加2=0-搜答案-智慧作业帮

等于37因为：【】都是一样的数字的话那他们就可以合并同类项：[]{10+1}*5=1980所以算出为37~

∵A={x|x^2-3x+2=0}∴A={1,2}B={x|x^2-ax+(a-1)=0}∴B={a-1,1}B包含于A,那么a-1=1或者a-1=2所以a=2或3C={x|x^2-bx+2=0}C包

x^2-3x+1=0x+1/x=(x^2+1)/x=(x^2-3x+1+3x)/x=(0+3x)/x=3x^2+1/x^2=(x+1/x)^2-2=3^2-2=7

x平方加y平方减2xy减6x加6y加9=0x^2+y^2-2xy-6x+6y+9=0(x^2+y^2-2xy)-6(x-y)+9=0(x-y)^2-6(x-y)+9=0(x-y-3)^2=0x-y-3

题意是这样的吧：求(x²+9x)/(x²+3x)+(x²-9)/(x²+6x+9)原式=(x²+9x)/(x²+3x)+(x+3)(x-3)

2x^2-6x+3=02x-6+3/x=02x+3/x=6平方(2x+3/x)^2=364x^2+9/x^2+12=364x^2+9/x^2=24

6x加2x的平方减3x加x平方加1=3x^2+3x+1,代入X＝－5时,其值＝61

你的题目是错的,

2x^2-3x+1=0(2x-1)(x-1)=02x-1=0x=1/2x-1=0x=1

(x-1)(x+2)(x+3)(x+6)+20=0(x-1)(x+6)(x+2)(x+3)+20=0(x^2+5x-6)(x^2+5x+6)+20=0(x^2+5x)^2-36+20=0(x^2+5x

(x-3)²+4x(x-3)=0(x-3)[(x-3)+4x]=0(x-3)(5x-3)=0x1=3,x2=3/59(x-2)²=4(x+1)²3(x-2)=2(x+1)

2/(x+3)(x-3）+(x-2)/x(x-3)=1/x(x+3)两边乘x(x+3)(x-3)2x+x^2+x-6=x-3x^2+2x-3=0(x+3)(x-1)=0x+3在分母,不等于0所以x=1

2x²-3x+6=0∵a=2,b=-3,c=6b²-4ac=(-3)²-4×2×6=9-48=-39＜0∴原方程无实数根.

x/x-3减x+6/x^2-3x加3/x=[x*x-(x+6)+3(x-3)]/x(x-3)=(x^2-x-6+3x-9)/x(x-3)=(x^2+2x-15)/x(x-3)=(x+5)(x-3)/x

-x^2+2x+3=0x^2-2x-3=0(x-3)(x+1)=0x=3或x=-1

2x²-18=x²+x²-1+2x-18=-1+2x2x=-17x=-17/2

原式=x³-2x²-x²+x+2=x²(x-2)-(x²-x-2)=x²(x-2)-(x-2)(x+1)=(x-2)(x²-x-1

再问：5+5²+5³+5^4+5^5+5^6+5^7+5^8...+5^2003再答：

4x²+3x-2=0△=9+4×2×4=41x=(-3±√41)/8再问：△=9+4×2×4=41这个是哪里来的呀如果这是一道问答题那它有没有实数解，有几个解再答：△=9+4×2×4=41＞