Manny works 40 hours per week. he must work for his parents where he earns $8 per hour. he also works for a computer company where he earns 20$ per hour. how many hours can manny work for the computer company to earn a total of $464 per week from both jobs?

x - number of working hours for parents

y - number of working hours for a computer company

{x + y = 40

{8x + 20y = 464

{x = 40 - y

{8(40 - y) + 20y = 464      || : 4

{x = 40 - y

{2(40 - y) + 5y = 116

{x = 40 - y

{80 - 2y + 5y = 116

{x = 40 - y

{80 + 3y = 116      || - 80

{x = 40 - y

{3y = 36       || : 3

{x = 40 - y

{y = 12

{x = 40 - 12

{y = 12

{x = 28

{y = 12