+0  
 
0
46
1
avatar

If you buy 7 hamburgers and 3 slices of pizza from the Sizzler, you get Sl in change back from a
$20 bill. If you buy 8 hamburgers and 2 slices of pizza, you get $0.50 back from a $20 bill. Find
the price of a hamburger and the price of a slice of pizza.

 Feb 16, 2020
 #1
avatar
+1

 

If you buy 7 hamburgers and 3 slices of pizza from the Sizzler, you get Sl in change back from a
$20 bill. If you buy 8 hamburgers and 2 slices of pizza, you get $0.50 back from a $20 bill. Find
the price of a hamburger and the price of a slice of pizza.
  

 

See the part I highlighted in blue?  Sl doesn't make sense, so I'm going to assume you meant $1. 

 

Let H stand for the price in $ of a hamburger, and

Let P stand for the price in $ of a slice of pizza. 

 

So                                    7H + 3P  =  20 – 1       =  19.00 

and                                  8H + 2P  =  20 – 0.50  =  19.50 

 

Multiply both sides of the 1st equation by 2 and get       14H + 6P  =  38.00 

Multiply both sides of the 2nd equation by 3 and get      24H + 6P  =  58.50 

 

Subtract the fourth equation from the third and get       –10H  =  –20.50  

Divide both sides of this equation by –10 and get               H  =  2.05 

 

Plug 2.05 into the first equation in place of H                   (7)•(2.05) + 3P  =  19.00 

                                                                                                            3P  =  19.00 – 14.35  =  4.65 

                                                                                                              P  =  1.55 

 

.

 Feb 16, 2020
edited by Guest  Feb 16, 2020

53 Online Users

avatar
avatar
avatar
avatar
avatar
avatar