bⁿ =brad natural
bᵃ =brad artificial
bⁿ =20/100 *bᵃ +bᵃ
bⁿ+ bᵃ=220 lei
(20/100 * bᵃ +bᵃ) + bᵃ =220
(2/10 * bᵃ + bᵃ) + bᵃ=220
{(2bᵃ/10) + (10bᵃ/10)} +bᵃ =220
amplificam:
12bᵃ/10 + 10bᵃ/10=2200/10
22 bᵃ /10 = 2200/10⇒bᵃ = 100 lei
bⁿ =220 - 100 = 120 lei
brad artificial = 100 lei
brad natural = 120 lei
