简便计算,计算的过程,因为是递等式

(10/27)*18*(3/5)
=(10*18*3)/(27*5)
=(2*2*1)/(1*1) 约分
=4
(11/13)(26/11)+2/13
=26/13+2/13
=28/13
(5/6)*(8/15)*(3/4)
=(5*8*3)/(6*15*4)
=(1*1*1)/(1*3*1)
=1/3
(7/13)*4+(6/13)*4
=(7/13+6/13)*4 结合律
=1*4
=4
(7/18+5/9)*(27/35)
=(7/18+10/18)*(27/35)
=(17/18)(27/35)
=17*27/(18*35)
=17*3/(2*35)
=51/70
99*(1/100)
=99/