TEST 4

SCANTRON ANSWERS: A B B B B    C A B A D      C B A B A    B B C C A    C C

Sec. 4.3

23.  Add.   (8a2   +  4a   - 7)  +  (10a2  -  3a   - 1) = 18a2   +  a   -  8

24.   Subtract.   (7a2   -  3a   - 2) - (2a2  - 6a   - 2)   = 5a2   +  3a

Sec. 4.4

25.  Multiply.   (7a8)*(4a2) = 28a12  .

26.  Multiply. Simplify by combining like terms.  (x + 2)*(x + 3)   = x2   +  5x   +  6

27.  Multiply. Simplify by combining like terms. (t  -  4)*(t + 3)   =  t2   -  t   -  12

Sec. 4.5

28. Multiply. Simplify by combining like terms. (a + 6)*(a + 6) = a2   +  12a   + 36

29. Multiply. Simplify by combining like terms.  (x +7)*(x - 7) = x2 - 49.

Sec. 4.6

30.  Combine like terms.  19a  +  b -  8a -  5b   = 11a - 4b

31. Add. (7r3 + 12rs - 4r2) + (2r3 - 3rs + r2 ) = 9r3 + 9rs - 3r2    = 9r3  -  3r2   +  9rs

32. Subtract. (7r3 + 2rs -5r2) - (2r3 - 4rs +  r2 ) = 5r3 +  6rs   -  6r2   =   5r3  -  6r2    +    6rs

Sec. 4.7

33. Divide. (30t3 -  10t2  -  25t)/5t.  = 6t2   -  2t   -  5 . Note we use a different symbol for division , but both mean the same thing.

34. Divide.   Following the rules presented in class, 1'.   Divide x2 by x to get x. 2'.   Then multiply x  and (x + 5) to get  x2 + 5x on the 2nd line down. .  3'.   Subtract  x2 + 5x  from  x2 + 2x to get  -3x. 4'.   Bring down the - 15 to get -3x - 15 on the 3rd line down.  5'.   Divide  -3x by x to get -3. 6'.   Multiply -3 and   (x + 5) to get -3x - 15 on 4th line down. 7'.   Subtract -3x  - 15 on 4th line   from -3x - 15 on 3rd line  to get ZERO REMAINDER. 8'.   The answer is x - 3,  placed above the first line, i.e., above the division symbol.

Sec. 4.8

35.  Express with positive components 4-5  = 1/45  .

36.  Express with negative exponents  1/62   =  6-2.

37.  Simplify (x3)-6 = x - 18 = 1/ x18  .

38.  8.13x104 = 81300

39.  4.32x10-4 = 0.000432.