18: X / 12 = 3:5, how to set up this equation?

18: X / 12 = 3:5, how to set up this equation?

18:X/12=3:5
x/12*3=18*5
x/4=90
x=360

How to set up the equation 18 △ x = 12
The teacher taught us that the value of X should be divided by a non-zero number on both sides of the equation, but if x is required, it should be 18 △ 12. How to write it? I'll add extra points if I get it right!

You can multiply both sides by X, and then divide them by 12

Solution equation: X / 4 + 8 = 2008 40% x-1.6 = 12 24:2 / 3 = x: 0.5
X/4+8=2008
40%X-1.6=12
24:2/3=X:0.5
4X-12=6
X divided by 3 + 0.6 = 3
(x-1.5) times 4 = 26
3x+4+x=80
x/3-x/6=2.4
60+3x-x=80
1.5x+36=x+45

x/4+8=2008 ==> x=800040%x-1.6=12 ==>x=3424:2/3=x:0.5 ==>x=724x-12=6 ==>x=4.5x/3+0.6=3 ==>x=7.2(x-1.5)*4=26 ==>x=83x+4+x=80 ==>x=19x/3-x/6=2.4 ==>x=14.460+3x-x=80 ==>x=101.5x+36=x+45 ==>x=18

X = () is the solution of the equation 4x + 15 = 27

4x+15=27
4x=12
x=3