Răspuns:
Explicație pas cu pas:
x/y = 2/7
a)
2x/3y = 2/3*x/y = 2/3*2/7 = 4/21
b)
(x + y)/y = x/y + y/y = x/y + 1 = 2/7 + 1 = 2/7 + 7/7 = 9/7
c)
x = 2y/7
y - x = y - 2y/7 = 7y/7 - 2y/7 = 5y/7
(2y/7)/(5y/7) = 2y/7*7/5y = 2/5
d)
x = 2y/7
2x + 3y = 4y/7 + 21y/7 = 25y/7
(25y/7)/5y = 25y/35y = 5/7
