x/12+20-x/3=x/4+30-x/5
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
x/12+20-x/3=x/4+30-x/5
4x-3x(20-x)=5x-7x(20-x)
4x-3x(20-x)=5x-7x(20-x)的解法
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?
x-(1/5+1/5)x-39=39 x-1/4x-2/5x=112 x-1/6x-1/3x-12=20
2x+3x+4x+5x+x+6x+7x=100
用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+.
4(x+3)=2x+2 7(x-1)=2x+3 4x+20=6x-30 4x-12=2x 2x-3=x+7 3x-4=2
解方程:x/2+x/6+x/12+x/20+x/30=5
x/2+x/6+x/12+x/20+x/30=5