The formula for slope is 
In this case:

so...


-1 <<<The slope
Hope this helped!
~Just a girl in love with Shawn Mendes
Answer:
Sₙ=3(1/2^n)
Step-by-step explanation:
Notice that in the given series that each term is being multiplied by 1/2, which is our common ratio. 3/2 is the first term because 3*1/2=3/2, so the expression that defines Sₙ is Sₙ=3(1/2^n)
This is not an Equation! this is an Sentence in Al Jebra!
but you means : if 3ax+b=c, then x =?
3ax=c-bX =