Key To Practice Midterm III

Problem 1

[-b +- sqrt(b²  - 4ac)]/2a

Problem 2

$1500 was invested at 4% and $3000 was invested at 5%.

Problem 3

 Done in class

Problem 4

A.  Dis = 9 + 20 = 29 hence two irrational roots.

B.  Dis = 49 - 48 = 1 hence two rational roots.

C.  Disc > 0 hence two roots

Problem 5

(4,2)

Problem 6

Done in class

Problem 7

A.  -1/12 +- i sqrt(47)/12

B.  +-i sqrt(2)

Problem 8

1+- i sqrt(3)

Problem 9

A.  -1/3 +- 1/3 sqrt(13)

B.  0 or 1

Problem 10

75/2 N