Question 905849: the sum of two numbers is 80 and their difference is half their addition. find the numbers. Found 2 solutions by 100601, MathLover1:Answer by 100601(6) (Show Source):
You can put this solution on YOUR website! Substitute the numbers for x and y. This will be a system of equations, which means that there will be two or more equations.
x= one of the numbers
y= one of the numbers
x+y= 80
x-y=1/2(x+y)
Substitute x+y for 80.
x-y=1/2(80)
x-y=40
Now that you've simplified the equation, here are the two equations:
x+y=80
x-y=40
You can subtract the two equations from each other:
(x+y=80)
- (x-y=40)
----------
2y=40
y=20
Because y=20, x=60 since y+x=80.
You can put this solution on YOUR website!
given:
the sum of two numbers, and , is : ..............eq.1
and their difference is half their addition:
.............eq.2
solve the system:
..............eq.1 .............eq.2
_______________________________add both
find