Answer:

Step-by-step explanation:
Hello,
let's find a and b reals so that


we identify the terms in 
9 = 3a
we identify the terms in x
-18 = 3b + a
we identify the constant terms
-7 = b
so ti goes with a = 9/3 = 3, b = -7
so we can write

so 
hope this helps
The slope is negative one
I think there is more to the question, but the equation to solve for the number of months until Rita has enough money to put a down payment for a condominium is 15,000=8,000+850X
Step-by-step explanation:
hope it's helpful for you
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