Answer:
use a calculator
Step-by-step explanation:
Slope = rise/run =[y2-y1]/[x2-x1]
1) slope = [90 - 30] / [12 - 4] = 60 / 8 = 15/2
2) slope = [75 - 30] / [10 - 4] = 45 / 6 = 15 / 2
The slopps are equal.
Answer:


The interval notation is: 
Step-by-step explanation:


