(1)x:6=2:5
5x=12
x=12/5
x=2.4
(2)3.6x=1.8*3
3.6x=5.4
x=5.4/3.6
x=3/2
x=1.5
(3)368x=276*4
368x=1104
x=3
(4)25*(20-x)=30*15
500-25x=450
25x=50
x=2
(1)x:6=2:5
5x=12
x=12/5
x=2.4
(2)3.6x=1.8*3
3.6x=5.4
x=5.4/3.6
x=3/2
x=1.5
(3)368x=276*4
368x=1104
x=3
(4)25*(20-x)=30*15
500-25x=450
25x=50
x=2