(1)(1/2x-2y)/(1/3+3/4y) (2)(0.2a-1/2b)/(3/4a+0.8b)

问题描述:

(1)(1/2x-2y)/(1/3+3/4y) (2)(0.2a-1/2b)/(3/4a+0.8b)

3x^3-x^3(6x+4y)-2[x^3+3(3x-2y)],其中x=1/5,y=3/4.3x^3-x^3(6x+4y)-2[x^3+3(3x-2y)]=3x^3-6x^4-4x^3y-2[x^3+9x-6y]=3x^3-6x^4-4x^3y-2x^3-18x+12y=x^3-6x^4-4x^3y-18x+12y=(1/5)^3-6*(1/5)^4-4*(1/5)^3*(3/4)-18*1/...