1. a)x/2 = y/3 = z/4 = t/5
y/3 = t/5 4y/12 = 2t/10 = (4y + 2t)/22 = 132/22 = 6
y/3 = t/5 = x/2 = z/4 = 6 y = 18 t = 30 x = 12 z = 24
b) 12/30 ₓ100 = 40 %
2. x = (-2)²⁰¹²ₓa⁵ₓb⁷ₓc⁴ = 2²⁰¹²ₓa⁵ₓb⁷ₓc⁴ x > 0
y = (-2)²⁰¹³³ₓa³ₓbₓc⁶
daca a>0, b > 0 y <0
daca a >0, b< 0 y > 0
daca a < 0, b <0 y < 0
z = (-2)²⁰¹⁴ₓa¹¹ₓb¹³ₓc⁸ z > 0
a) x > 0 z >0
b) x > 0 y < 0