135*852852-852*135135= 135*852*1001-852*135*1001=0
9/13+13/9+11/13+14/9+6/13= 9/13+11/13+6/13+14/9+13/9=(9+11+6)/13+(14+13)/9=2+3=5
(1+1.2)+(2+1.2*2)+(3+1.2*3)……(100+1.2*100)
= (1+2+3+……+100)+1.2*(1+2+3+……+100)
=2.2*(1+2+3+……+100)
=2.2*5050
=11110
(3.6*0.75*1.2)/(1.5*24*0.18)
= (3.6*1.5*0.5*1.2)/(1.5*12*2*0.18)
=0.5
1.234*3456.7+0.1234*12345+0.01234*530880
=1.234*(3456.7+1234.5+5308.8)
=1.234*10000
=12340