Question

x-4/9=3x/4 и x-7/4=3x-2/5

Answer 1

1) x-4/9-3x/4=0 
36x-16-27x=0
9x-16=0
9X=16     | :9
X=16/9
2)   x-7/4-3x+2/5=0 *20
20x-35-60x+8=0
-40x= 27       | :     ( -40)
X= -27/40
X= -0,675