1364+4578=5942
6453+1469=7922
80 000kg= 80 tấn
135+360+65+40
=( 135+65) + (360+40)
= 200 + 400
= 600
18.(x-16)=18
(x-16)=18:18
(x-16)=1
x=1+16
x=17
1364+4578=5942
6453+1469=7922