Which of the following is a complex number?

-7

2 + StartRoot 3 EndRoot

4 + 9i

Pi

Add and simplify (-4+n-2n^2) + (2-5n-6n^2)

What single percentage change is equivalent to a 15% decrease followed by a 16% decrease?

What is the cost of 12 bottles explain

Find all complex solutions of 3x^2-x+4 = 0.

Is x2 + 7x + 49 a perfect square trinomial?

Half angle tan 5pi/8

Explain how three numbers form a Pythagorean triple

To the nearest hundred, what is the greatest whole number that rounds to the 2,500? the least whole number

An art teacher had 2/3 gallon of paint to pour into containers. If he poured 1/8 gallon of paint into each container until he ran out of paint how many containers can he fill

A freight train leaves the station traveling at 30mi/hr. One hour later, a passenger train leaves the same station on a parallel track traveling at 60 mi/hr. How far from the station does the passenger train overtake the freight train