1.a) 3/4x =27=> 3x= 108=> x=27
b) 30/100 x = 15=> 3x= 150=> ×=50
c) 40/100x =28=> 4x= 280=> x=70
2. 2x +3 y=24
x/y=3/4=> 4x=3y=> x=3y/4
3y/4 + 3y = 24
3y + 12y= 96
15y= 96
y=96/15
y=32/5
2x + 96/5 =24
10x + 96 = 120
10 x= 24=> x= 24/10=> x= 12/5
V: 24/5 + 96/5 =24
24 + 96= 120 A
3. 4x-3y/ 3x-y= 1/5
3x-y= 20x-15y
17x=14y
x/y= 14/17
iar la ultimul nu stiu la ce se refera