x/2=5/12
12x=2×5
12x=10
x=10/12=5/6
y/3=5/12
12y=3×5
12y=15
y=15/12=5/4
z/7=5/12
12z=5×7
12z=35
z=35/12
x+y+z=5/6+5/4+35/12 - aducem la acelasi numitor....12
x+y+z=10/12+15/12+35/12
x+y+z=60/12
x+y+z=5
x / 2 = 5 / 12 ⇒ 12 x = 10 ⇒ x = 10 / 12 = 5 / 6
y / 3 = 5 / 12 ⇒ y = 15 / 12 = 5 / 4
z / 7 = 5 / 12 ⇒ z = 35 / 12
x + y + z = 10 / 12 + 15 / 12 + 35 / 12 = 60 / 12 = 5
Raspuns: x + y + z = 5
