Răspuns:
1. x = 1
2. 3/5
3. 2/5
Explicație pas cu pas:
1.2/ 3 = x / 2.5
x = 2.5*1.2 / 3
x = 2.5*0.4
x = 1
2.
b = 3a
(3a + 2b) / 5b =
(3a + 2*3a) / 5*3a =
(3a + 6a) / 15a =
9a/15a =
9/15 =
3/5
3*(4a+5b) = 9*5b
12a + 15b = 45b
12a = 30b
a = 30/12 * b
a = 5/2 * b
a/b = (5/2 * b) / b = 5/2 / 1 = 2/5
