What term should be added to create a perfect square trinomial?

x^2+18x

i think it's + 81 but i'm not positive.

10, 15, 8, 12, 18, 17, 20 Find the mean number of movies that the students saw. If necessary, round your answer to the nearest tenth.

What is 3/4 + (-5/12)

If S is the sum of the integers from 51 to 150 and T is the sum of the integers from 151 to 250, what is the value of S-T

Lucinda bought 6 shirts that were $18 each. She also bought a pair of jeans for $35.79. What was the total amount Lucinda pald for the shirts and jeans?

Times for an ambulance to respond to a medical emergency in a certain town are normally distributed with a mean of 450 seconds and a standard deviation of 50 seconds. suppose there are 288 emergencies in that town.

Joseph says that there is 5/8 of a ham sandwich left and 1/2 of a turkey sandwich left what is not a pair of equivalent fraction for 5/8 and 1/2

Aspen added 14 to the product of 224 and 16. What is the sum?

the number 42,__2 rounded to the hundred place is 42300. what is the least possible sum of the two missing digits? justify your answer.

What were Greek tyrants like?

Is 4b²+40b+20 a perfect square