4x^2-x^3-4x怎么做

(x-4)(x-3)-(x-2)(x-3)怎么做 1/(1-x)+1/(1+x)+2/(1+x*x)+4/(1+x*x*x*x)+8/(1-x*x*x*x*x*x*x*x)怎么做 x-1/x-2-x-3/x-4=x-2/x-3-x-4/x-5怎么做? 4x^2-x^3-4x怎么做 (2x 3)*x等于5x-4怎么做 4x-14=(x+2)*(x-3)怎么做 x+6+2x-3-4x怎么做 x*x^3+(-2x^2)^2+14x^6/(-4x^2)怎么做? x*x^3+(-2x^2)^2+14x^6/(-4x^2)怎么做? 3x（x^2+4x+4）－x（x-3）（3x+4）怎么做, x^4-1-4x^2-4x怎么做 x^4-1-4x^2-4x怎么做? ∫(2^x*3^x)/[(4^x)+(9^x)]dt怎么算?今天同学问我∫(2^x*3^x)/[(4^x)+(9^x)]dt怎么做, X(X-4)=3X+1怎么做 x^2+x(x+4)=30怎么做 x^2+x(x+4)=30怎么做 (3/x+2)+1/x=4/x²+2x这道题怎么做 (x+1)(x+2)(x+3)(x+4)-24怎么做+++++++++++++++++++++++++