Answer: -2
Explanation: On the image we can see it goes down 4 units and right 2. Giving us the slope 
Simplified that is -2 which is the slope of the line
Answer:

Step-by-step explanation:
start by foiling out the given function

next, use the power rule to find the derivative
power rule: To use the power rule, multiply the variable's exponent n, by its coefficient a, then subtract 1 from the exponent. If there's no coefficient (the coefficient is 1), then the exponent will become the new coefficient.

If there is 10% of $18 = 18 x 0.9 (1 - 0.1) = $16.20
Therefore the pie costs $16.20
He is saving 18 - 16.20 = $1.80