Relationship between mini and kabuliwala

The relationship between Mini and the Kabuliwala is as follows:The Kabuliwala is a travelling dried fruit seller from Afganistan. He left his wife and daughter behind in Afganistan while he traveled around Kolkata, India selling his dried fruit. Mini is a happy girl and loves to talk all day. She reminds the Kabuliwala of his daughter so he befriends her and gives her dried fruit and nuts. Mini's father notices she has the fruit and nuts from the Kabuliwala and gives him a half rupee coin. 

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4

answer: x = 4 and y = 4