Oi :)
1) There are 3 significant digits

2)
15 Mi/h = 22 ft/s
3)

4)
There are 4 significant digitis. Leter C
A y-intercept always has to have an x-value of 0 so the answer is D (the last option)
Answer:
Question 1 = 32.4ft Question 2 = 72ft Question 3 = 288ft
Step-by-step explanation:
Use multiplication.
Your equations are right. just use the substitution method to solve. substitute y because both have that on one side
it'll look like 40x+30=30x+60.
then just get x in one side. I showed my owrk in the photo