减去负3x等于5x平方-3x-1的代数式是-搜答案-神马作文网

x²-5x=14x²-5x-14=0(x-7)(x+2)=0x1=7x=-2x²-3x+2=7²-3x7+2=30或x²-3x+2=（-2）²

x/(y-x)

再问：再答：字模糊再问：

3×5½

得到:X^2-15X=-56X^2-15X+56=0(x-7)(x-8)=0所以X=7或者x=8

x^2+3x-1=0(x+3/2)^2-13/4=0(x+3/2+√13/2)(x+3/2-√13/2)=0x=-3/2-√13/2或x=√13/2-3/2

x-1/x=3x^2-3x-1=0(1)(1)*x得：x^3-3x^2-x=0(2)(1)*2得：2x^2-6x-2=0(3)(2)+(3)得：x^3-x^2-7x-2=0所以：x^3-x^2-7x+

由2x^2-3x-4=0得：x^2-2=3x/2所以x-2/x=(x^2-2)/x=(3x/2)/x=3/2

(x+1)/(x^2-x)-1/3x=(x+5)/(3x-3)3(x+1)/(x^2-x)-1/x=(x+5)/(x-1)3(x+1)-(x-1)=x(x+5)3x+3-x+1=x^2+5x2x+4=

x+1/x=3(x+1/x)^2=9x^2+1/x^2+2=9x^2+1/x^2=7x^2+1/x^2-2=7-2(x-1/x)^2=5x-1/x=±√5x^2-1/x^2=(x+1/x)(x-1/x

正负3根号5

=∫-x²/5x²dx=∫(-1/5)dx=-x/5+C=∫9^x*e^xdx=∫(9e)^xdx=1/ln(9e)*∫ln(9e)*(9e)^xdx=(9e)^x/ln(9e)+

m=2n=4/3因为是5次所以2+m+1=5所以m=23n+3-m=5所以3n=2+m又m=2所以3n=4所以n=4/3

3x^2-5x-2002=1=>3x^2-5x=20035x-3x^2=-200315x-9x^2+2008=3(5x-3x^2)+2008=3×（-2003）+2008=-4001

-(-3x)=(5x)^2-3x-525x^2-6x-5=0此多项式为：25x^2-6x-5

x/(x-3)-5x/(x^2-x-6)=(x^2+2x)/(x^2-x-6)-5x/(x^2-x-6)=x/(x+2)

x²-3x=1,利用配方法:x²-3x+9/4=1+9/4(x-3/2)²=13/4x-3/2=±√13/2x=(3±√13)/2也可以用求根公式法解:x²-3

解代数式=(-3-5x+4x²)+(-3x²+2x²)=-3-5x+(4x²-x²)=-3-5x+3x²