(15+5x)*2/5=2/3*1.
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6)
2x+3x+4x+5x+x+6x+7x=100
5x+15/x^2+x-6=A/x-2+B/x-3
(5X-15)-(2X+3)=X+12
15-(4-5x)=2x+(35-3x)
5[x^2-x]=3[x^2+x]
x-3/5x=2/15
7X=2X+15 15=7X-2X 15=5X 5X=15 X=15/5 X=3
(2x-1)/(x-1)(x-2)=(x-5)/(x-2)(x-3) x/2x^2-11x-21=(x+7)/x^2-1