Apps. and Interpretation for IBDP Maths Ebook 1 | Seite 373

Answers
29.4 (a) 5x� y� 20 � 0
(b) L
1
and L
2
are perpendicular
Exercise 30
30.1 (a) The gradient of L
1
is 1 2
The y -intercept of L
1
is 8
(b) x� 2y�12 � 0
30.2 (a)
3
�
2
(b) a �� 4
(c) 3x� 2y�11 � 0
30.3 (a) The gradient of L
1
is � 3
The x -intercept of L
1
is � 7
(b) x�3y� 7 � 0
30.4 (a) (i)
1
2
(ii)
17
�
4
(b) 8x� 4y�17 � 0
(c) b �� 5
Exercise 31
31.1 (a) � 3
(b) 3x� y� 6 � 0
(c) y� �3x�
6
(d) ( � 1, 3)
(e) x�3y�10 � 0
(f) k � 3
31.2 (a) k � 20
(b)
1
4
(c)
1
y� x�
20
4
(d) y� �4x�
20
(e) 4x� y�80 � 0
(f) r � 16
(g)
�240 400 �
� , �
� 17 17 �
31.3 (a)
2
�
3
(b) 2x �3y �6k
� 0
(c) k � 10
(d) 3x� 2y�50 � 0
(e) h � 15, k �� 2.5
(f) a � 0.1
(g) 10 and 20
31.4 (a) a �� 4 , b � 2
(b) � 16
(c) h �� 1, k �� 18
(d) 6
(e) 6x� y�12 � 0
(f) (i) d �� 96
(ii)
8
d �
3
Exercise 32
32.1 (a)
1
�
2
(b) x� 2y� 200 � 0
(c) m � 2 , c � 0
(d) (40, 80)
(e) 2000
(f) r � 4
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363