3333*3333+9999*8889
=3*3333*1111+9999*8889
=9999(1111+8889)
=9999*10000
=99990000
1/3*x+1/4*x+5=x
x-7/12*x=5
5/12*x=5
x=5*12/5
x=12
18*七分之五-5*七分之四
18*5/7-5*4/7
=(90-20)/7
=10
27*3.4+15.4*34-8.1*34
=34*(2.7+15.4-8.1)
=34*(2.7+7.3)
=34*10
=340