C because i did it and got it right
Answer:
The rule is: y = -10x+85
Step-by-step explanation:
The rule is given by:

Here m is the gradient and b is the y-intercept.
We have to take two pairs of input-output to find the rule
Let the two pairs be:
(x1,y1) = (1,75)
(x2,y2) = (2,65)
Slope is found using the formula:

Putting the values

Putting the value of slope

Putting a pair of input-output in the equation (1,75)

Putting the value of b

Hence,
The rule is: y = -10x+85
42.86 From a Google calculator search.
X=2 for the top & for the bottom 3/4y+15/4