Grade 9 math

Question

Susan charges a flat rate of $20 per night of babysitting. She also charges an extra fee of $3 per hour for every hour she works past 8pm. If susan received $32 for a night of babysitting. how late did she work?

 

We are currently learning about linear equations

Answer 1

in order to solve this one you want to subtract the earned amount from the flat rate and then divide by 3 to convert over into hours. when i do that i get

($32 - $20)/$3 = $12/$3 = 4 hours beyond 8:00 p.m.

that means that she worked until midnight

Answer 2

 Y - money received

 

  X - hours worked beyond 8 PM

 

   Y = 3 X + 20

 

    32 = 3X + 20

 

    12 = 3X

 

   X = 12/3 = 4    / number of hours work beyond 8:00 PM, till 12:00 PM.