Respuesta :

x =7.5 
this is because you would cross multiply to get 12x=90. You would have to isolate the variable by dividing both sides by 12. that leaves you with x=7.5
Hello There!

First solve the numerical side:
9/4 = 2.25
So now we know:
3x/10 = 2.25
Multiply both sides by 10:
3x/10  x 10 = 2.25 x 10
Simplify it:
3x = 22.5
Divide both sides by 3:
3x/3 = 22.5/3
Simplify it:
x = 7.5

3(7.5)/10 = 9/4

Hope This Helps You!
Good Luck :) 

- Hannah ❤