Tìm x

Bai: 1. Tim x, birt.
a, a (x-1) - 5 (x+²) = -10
b₁ x (5-dx) + 2 x (x - 1) = 15
C₁ 3 (x-2) (5-x) + (3x-4) (2-1) = -1
01₁ 2x + 1 = 1
21-3
Q