Question 114504

THERE ARE TWO WAYS (MAYBE MORE) TO WORK THIS:

LETS DO THE EASY WAY FIRST, THEN I WILL SET UP THE HARD WAY AND YOU CAN FINISH IT.

Let x=one number
Then 39-x=the other number

Now we are told that:

(39-x)-x=7  get rid of parens (distributive law)

39-x-x=7 subtract 39 from both sides

39-39-x-x=7-39  collect like terms

-2x=-32  divide both sides by -2
x=16-------------------one number

39-x=39-16=23------------the other number

CK
their difference IS 7 and their sum IS 39


THE HARD WAY:
Let x=one number 
And y=the other number

x+y=39----------------------------eq1
x-y=7--------------------------eq2

substitute x=39-y from eq1 into eq2 and we get

x-(39-x)=7 get rid of parens

x-39+x=7  add 39 to both sides
x-39+39+x=7+39 collect like terms

2x=46

Now you finish this one


Hope this helps---ptaylor