(4x-13):(x+ 13)=7:
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
4x+9x=13x
(4x-13):(x+ 13)=7:
7+4x=-2x+13
2x-7/4x=13 3x+1/3x=20/21 x-0.28x=12.
解方程:13x+8=11x -7x+2=2x-4 3x+2=-3+x x-3=-1/2x
3x^-12x-2根号(x^-4x+7)+13=0
3x+2(4X+6)=3(6X-15)-13 3X-4(2X+5)=7(x-5)+4(2X+1)
若x=π/3,|x+1|+|x+3|+...+|x+13|-|x+2|-|x+4|-...-|x+12|
3x+1=5x+2=7x+4=13x+6 求x等于多少?
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
已知2x*x+x-5=0,求代数式6x*x*x+7x*x-13x+11的值