Answer:
a - a or (a +(-a))
Step-by-step explanation:
A negative plus a positive is always zero if they have the same variable.
Let x = months
so we know that price of software package is $20
Now we need to find x the price of one month
we know that Angie and Kenny spent 115 total
Angie: 20 + 3x ( one software pack + 3(price of one month)
Kenny: 20+ 2x ( one software pack + 2( price of one month)
So Angie + Kenny = $ 115
20 + 3y + 20 + 2y = 115
combine like terms and solve for x. That will give you the cost of one month
40 + 5x = 115
-40 -40
5x= 75
5x/5 = 75/5
x=15
