218 Answer Key
of a circle and can be any real nonzero number, so r is a variable. The numbers 2
and π have fi xed, defi nite values, so they are constants.
- −12 is the numerical coeffi cient
- 1 is the numerical coeffi cient
4.^2
3 is the numerical coeffi cient - −5x= −5 ⋅ 9 = − 45
- 2xyz= 2(9)(−2)(−3) = 108
7.^6
510
6
5910
() 1 () 9 1
x
=
−
=
−
61 ⋅ 0
53 ⋅ 10
=
−
60
15 10
=
60
5
= 12
− ()−
−+
=
− + ()⋅ ()
− ()+()−
25 +
6
22 − (^5) ( −(−
(^3366) (()(− ()
y+ (^5) (
zy+
− + ()
− ()−
22 ⋅ (^5) ( +
(^6) (− 8
− +
− −
22 ⋅ 52 ⋅ 0
6 ()− 3 8
=−+
−
4 100
18 8
96
10
= 9.6
- x^2 − 8x − 9 = 92 − 8 ⋅ 9 − 9
= 81 − 72 − 9
= 0 - 2y + x(y − z) = 2(−2) + 9((−2) − (−3))
= 2(−2) + 9 (−2 + 3)
= 2(−2) + 9(1)
=− 4 + 9
= 5