Răspuns:
Explicație pas cu pas:
a)
(3/4)*(x/y) = (3/4)*(2/5) = 3/10
b)
(3x + 2y)/3y = 3x/3y + 2x/3y = x/y + (2/3)*(x/y) = 2/5 + (2/3)*(2/5) = 2/5 + 4/15
= 6/15 + 4/15 = 10/15 = 2/3
c)
x/y = 2/5
x = 2y/5
2x + 3y = 4y/5 + 3y = 4y/5 + 15y/5 = 19y/5
7x - 2y = 14y/5 - 2y = 14y/5 - 10y/5 = 4y/5
(19y/5)/(4y/5) = (19y/5)*(5/4y) = 19/4
