C=1500+4x where x is cds, C is cost
R=10x where R is revenue
then, P=R-C
P=10x-1500-4x
P=6x-1500
set P=0
1500=6x
x=250
check, C=1500+4*250, R=10*250
C=250, R=250
They need to sell 250 cds before they make profit
Your speed is 13 ft/sec. In order to know our velocity, we would need to know what direction we're moving. You haven't told us anything about our direction, only that our speed is 13 ft/sec.
The answer is false.
A radius is a segment that connects any point on the circle to the center of said circle. An angle requires two lines, and a radius only consists of one line, which further proves that this statement is false.
4x - 2 = 2x + 8
2x -2 = 8
2x = 10
x = 5
4(5)-2 = 2(5)+8
20-2 = 10+8
18 = 18