0.4X=7/2*6/5

x=2 1/5*5/2

x=2 1/2

0.6:X= 1.5: 10

1.5x= 10*0.6

x=6/ 1.5

x=4

X: 1.2=5/ 12:5

5x= 1.2*5/ 12

x= 1/ 10

0.75:X=3: 12

3x=0.75* 12

x=9/3

x=3

1/2: 1/3 = 1/4:X

1/2x= 1/3* 1/4

x= 1/ 12*2

x= 1/6

4.2/7=54/X

4.2x=7*54

If X=90 is selected as a satisfactory answer, you can increase your experience value and wealth value at the same time.