Salut,
a) 5x = 21
x = 21:5
x = 4,2.
b) 0,17x = 2,89
x = 2,89/0,17
x = 289/17 (am amplificat cu 100)
x = 17.
c) 1,5x-0,6 = 7,5
1,5x = 7,5+0,6
1,5x = 8,1
x = 8,1/1,5 (am amplificat cu 10)
x = 81/15
x = 5,4.
d) 2,6x-1 = 2,4²
2,6x-1 = 5,76
2,6x = 5,76+1
2,6x = 6,76
x = 6,76/2,6 (am amplificat cu 100)
x = 676/260
x = 2,6.
e) 2,4x-2 = 2,32
2,4x = 2,32+2
2,4x = 4,32
x = 4,32/2,4 (am amplificat cu 100)
x = 432/24
x = 1,8.
Succes! :3