Answer:
r = 13
Step-by-step explanation:
The first step is to find b from y=mx=b using m=4/3 and (-4,8)

After solving the equation, b will equal -16/3 making the final equation be

Using the equation, you can solve for r.

This will bring the answer being r = 13
It would take 70,000 seeds if five out of seven are good. So over a quantity of 50,000 plants desired, you would sow 70,000 seeds. As 20,000 would statistically fail.
Answer To (b): 10 sandwiches in 20 minutes. But If Your Friend Arrived 10 Minutes Earlier, Then He Can Make 20 Sandwiches In The 20 Minutes That You Are There. If He Started When He Arrived And The Twenty Minutes Started Then, You Can Only Make 5.
Percent increase/decrease is:
(Change/original amount)x100
(.25/2.35)x100= 10.6%