解方程：7-2x+9=0

解方程：2x(x-9x)+16=0 解方程(3x^2+9x+7)/(x+1)-(2x^2+4x-3)/(x-1)-(x^3+x+1)/(x^2-1)=0 解方程:(x+3)/(x+2)-(x+5)/(x+4)=(x+7)/(x+6)-(x+9)/(x+8) 解方程】(x+8)/(x-3)-(x-9)/(x-4)=(x+7)/(x+8)-(x+2)/(x+3) 解方程：（x-8）/(x-3)-(x-9)/(x-4)=(x+7)/(x+8)-(x+2)/(x+3) 解方程：x/(x-2)+(x-9)/(x-7)=(x+1)/(x-1)+(x-8)/(x-6) 解方程 x*x*x + 2*x -19 =0 解方程4x^2+2x√(3x^+x)+x-9=0 解方程：9x^2+6x-9=0 解方程：7-2x+9=0 解方程：3X^2-9X+2=0 x^2-7x+2=0解方程,