第一道题：原式=4/7*348/13+4/7*4*4/13.
=(4/7)(348/13+16/13).
=(4/7)(348+16)/13.
=(4/7)*364/13.
=(4/7）*28.
=4*4.
=16.
第二道题：原式=(1/4)[(4.85*18/5+(6.15*18/5)-3.6] .
=(1/4)(0.97*18+1.23*18-3.6)
=(1/4)[(0.97+1.23)*18-3.6]
=(1/4)*(2.2*18-3.6).
=(1/4)*2.2*18-3.6/4.
=9.9-0.9.
=9.