
Question 11 :
the equations are :
now, let's graph the lines ~
As you can see in the attachment, The lines coincides each other, so the equations are :
There are 4 As and 3 Bs, so the ratio of Bs to the total number of As and Bs is ...
... (count of Bs) : (count of As + count of Bs)
... = 3 : (4 + 3)
... = 3 : 7
Expressed as a fraction, this is
... 3/7
Jacobs dog: $5 x 5 hours plus $ 12 service is $37
Jacks dog : $3 x 5 hours plus $18 service is $ 33
So it’s cheaper to go with jacks dog service