7^(X+4)=17……(-7x)
1x+2x+3x+4x+5x+6x+7x…+99x=100
(1) 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)
求和:Sn=1+3x+5x*x+7x*x*x+……+(2n-1)x^n-1 (x不为0和1)
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
2x+3x+4x+5x+x+6x+7x=100
X 7 X - X 7 X = X 9 8 X 9 X - X 9 X = 4 9
5x/(x+3)(x+2)+(2x-5)/(x-4)(x+3)=(7x-70)/(x+2)(x+4)
x-4/x-5 - x-5/x-6=x-7/x-8 - x-8/x-9求x=?
已知方程2(X+1.5X)=25,请填写下表: X 1 2 3 4 5 6 7 … 2(X+1.5X) ( ) ( )
f(x)=1+x-x²/2+x³/3-x^4/4+…+x^2013/2013
方程 3x(7-2x)+5x(2x-1)=4x(x-3)+56