The sum of two numbers is 80 and the difference of the same two numbers is 42.5. Find the numbers.

Question

 Help Please

Answer 1

x+ y =  80 

x- y = 42.5  

 

Add these two together  

 

2x  = 122.5   

x -  61.25  

 

y  =  18.75  

 

 

Answer 2

using algebra...

x+y=80

x-y=42.5

add

2x=122.5

x=122.5/2

x=61.25

y=80-61.25

y=18.75

 

using arithmetic...

80/2=40

42.5/2=21.25

40-21.25=18.75

40+21.25=61.25