Question

1.[(a+2/aXa-5a+2)+1]除以axa+4a+4/aXa-4,其中a=2+根号3

Answer 1

1 .[(a+2/(aXa-5a+2)+1]/((axa+4a+4)/(aXa-4))

=((√3+4)/(-1-√3)+1)*(√3)/(4+√3)

=-3√3/(7+5√3)=(21√3-45)/26

2 928/(1200/x-2)=4x/5 x=20

3 甲X天 乙x+6

1-(1/x+1/(x+6))*3=(x-3)/(x+6)

x=6

(1) 1.2*6=7.2

(2) 0.5*(6+6)=6

(3) (1.2+0.5)*3+(6-3)*0.5=6.6

施工方案(2)最省钱