Answer:
15
Step-by-step explanation:
14-5=9 (a)
21-9=12 (b)
9x9=81, 12x12=144
144+81=225

I think the answer would be "I spent 4 hours teaching lessons".
Answer:
yes,it can ................
Answer:
C
Step-by-step explanation:
Let x be the number of guests needed to cover the cost of the permit.
Each guest pays $1.25, then x guests pay $1.25x.
200 students attend the picnic, each student attending the picnic pays $0.75, then 200 students pay 
The total sum the students and the guest pay is

A local high school needs to purchase a park permit for $250.00 for their upcoming senior class picnic, then

So, correct option is C:
A local high school needs to purchase a park permit for $250.00 for their upcoming senior class picnic. Each student attending the picnic pays $0.75. Each guest pays $1.25. Suppose 200 students attend the picnic. What is x, the number of guests needed to cover the cost of the permit?