1. (07.02) What is the value of x in the equation 2x + 9 = 21?

2
6
9
15

X+ y = k 2x + 3y = k + 1 the point of intersection of the lines has an x-coordinate of a.2k + 1 b.-2k + 1 c.2k - 1

Tickets to a science exposition cost $5.75 each for studentd and $7.00 for adults.how many students and adults went if the ticket charge was $42.75

If the scale factor between two circles is 2x/5y what is the ratio of their areas?