What does an open circle represent and when would you use it

Can someone tell me What is half of 4/9

What is w' - 8.52 = 5.9

Can you fine the cube root of a negative number? If so, is it positive or negative? Explain your answer.

A new high school opens in a thriving suburban community. The number of students signed up to attend the school in its first year is 532, and the population of students is predicted to increase at a rate of 16% per year.

Three numbers are in the ratio 2 : 3 : 4. The sum of their cubes is 33957. Find the largest number

8, 18, 11, 15, 5, 4, 14, 9, 19, 1, 7, 17, 6, 16,?,?,?,?,? what are the last few numbers impossible

What term should be added to t^2+11t, to make it a perfect square trinomial?

Given: m∠AOC = 120°, m∠BOD = 150°. Find: m∠BOC.

Reduce to lowest terms 3m^2-3n^2/6m-6n Options A. - m-n/2 B. m-n/2 C. m+n/2

10.5 times what equals 110.3