5. By extracting square roots, how many real roots or solutions does the quadratic equation y2 - 16 = 0 have?
a. O
b. 1
c. 2
d. 3

6. What are the roots or solutions of quadratic equation m2 + 4m - 21 = 0 by using Completing the Square?
a. 3 and 7
b. 7 and -3
c. 1 and 21
d. 1 and -21​