18 first-graders and 72 other students attended a school assembly. what percentage of the students at the assembly were first-graders?

One integer is 8 times another. if the product is 72, then find the integers

If f(x) = 3x-2 and g(x) =2x+1 find (f-g)(x)

Masons cell phone company charges $0.12 for every text message he sends plus $2.50 per month if mason sent 25 messages this month how much money does he owe the one with the correct answer and explanation gets 10 points and is marked as the brainliest answer