Question

joao gasta 1/3 do seu salario no aluguel do apartamento onde mora e2/5 do que lhe sobra em alimentação ,ficando com 480,00 para as demais despesas .portanto, de joao é igual a:

Answer 1

Olá Cesar

x/3 + (x - x/3)*2/5 + 480 = x 

x/3 + 4x/15 + 480 = x

5x + 4x + 15*480 = 15x

15x - 9x = 15*480

6x = 15*480

x = 15*480/6 = 15*80 = 1200 reais 

Answer 2

Dados
X= salário de João. 1x/3= Aluguel. 2x/5= alimentação:                                          x - 1x/3= 2x/3                                                                                                     2x/3 - 2x/5 = 10x - 6x/ 15 = 6x/15                                                                             6x/15= 480                                                                                                                             6x= 480 x 15                                                                                                         6x = 7200                                                                                                                 x = 7200/ 6                                                                                                            x= 1200