What number should be added to the expression x2 + 4x to change it into a perfect square trinomial?
a: 1
b: 8
c: 2
d: 4

Which choice represents the sample space ,s for this event

1mile equals approximately 1.6 kilometers. which best approximates the number of miles in 6 kilometers?

It takes an ant farm 3 days to consume 1/2 of an apple. at that rate, in how many days will the ant farm consume 3 apples