11. e. x –1
=
1
x = =
–4; –
8
3
x = –
=
3
2
. 4
x + 3 =
4(–
1
4
) + 3 = –1 + 3 = 2; 16
x = 16
–
1
4
= =
1
2
;
8
1
1
x = =
81
1
4
= 3.
12. e. Angles
e and
f are vertical angles, so angle
e angle
f . However, angle
d and angle
j are not
alternating angles. These angles are formed by
different transversals. It cannot be stated that
angle
d angle
j , therefore, it cannot be stated
that
d +
e =
f +
j .
13. a. Melissa’s mean time for the first five dashes is
=
2
5
8
= 5.6. Her times, in order
from least to greatest, are: 5.3, 5.4, 5.4, 5.6, and
6.3. The middle score, or median, is 5.4. The
number that appears most often, the mode, is
5.4. A score of 5.3 means that the mean will
decrease and that the mode will no longer be 5.4
alone. The mode will now be 5.3 and 5.4. The
median, however, will remain 5.4.
14. b. = (
x y y +
xy )(
x x y ) =
x y +
x 15. a. If a straight line were drawn through as many of
the plotted points as possible, it would have a
negative slope. The line slopes more sharply
than the line
y = –
x (a line with a slope of –1), so
the line would have a slope more negative than
–1. The line would also have a
y -intercept well
above the
x -axis. The only equation given with a
slope more negative than –1 is
s = –2(
t – 15).
