Solve for x.
x^2 = 16
a. -4, 4
b. -8, 8
c. -16, 16
d. -32, 32

20 da is equal to a. 2,000 cm. b. 2 m. c. 20,000 cm. d. 20,000 mm

A. 127 cm^2 b. 144.5 cm^2 c. 172 cm^2 d. 50 cm^2

The half-life of a certain material is 0.002 second. approximately how much of a 14-gram sample will be left after 0.004 second? a. 12 grams b. 3.5 grams c. 0.06 gram d. 7 grams