a) 2(x + 1/5)=1 1/4
2x + 2/5 = 5/4 (numitorul comun 20)
2*20x + 2*4=5*4
40x+8=20
40x=20-8
40x=12
x=12/40=3/10
b)1/4(x + 6/7)=5/7
x/4 + 1/4*6/7=5/7
x/4 + 6/28=5/7 (numitorul comun 28)
7*x + 6 = 4*5
7x = 20-6
7x =14
x=2
c) 0,5(x + 2/9) = 0,75
5x/10 + 5/10*2/9 = 75/100
5x/10 + 10/90 = 75/100 (numitorul comun este 900)
5*90x + 10*10 = 75*9
450x+100=675
450x = 675-100
450x = 575
x=575/450 (simplificam prin 25) = 23/18
