4.2.2 Linear Equations I, PT3 Practice


Question 6:
Solve each of the following equations:
(a)  5 a 16 = a (b)  6 + 2 3 ( 9 p + 12 ) = p


Solution:
(a)
5 a 16 = a 5 a a = 16 4 a = 16 a = 4

(b)
6 + 2 3 ( 9 p + 12 ) = p 6 6 p + 8 = p 6 p p = 8 6 7 p = 14 p = 2


Question 7::
Solve each of the following equations:
(a)  a 2 = a 5 (b)  b 3 4 = 2 + b 5

Solution:
(a)
a 2 = a 5 5 a 2 = a 4 a = 2 a = 2

(b)
b 3 4 = 2 + b 5 5 b 15 = 8 + 4 b 5 b 4 b = 8 + 15 b = 23

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Question 8:
Solve each of the following equations:
(a)  x = 24 x (b)  y + 5 4 ( 4 2 y ) = 4

Solution:
(a)
x = 24 x 2 x = 24 x = 12

(b)
y + 5 4 ( 4 2 y ) = 4 4 y + 20 10 y = 16    ( × 4 ) 6 y = 16 20 6 y = 36 y = 6


Question 9:
Solve each of the following equations:
(a)  5 p = 8 p 9 (b)  3 q = 20 13 q 4

Solution:
(a)
5 p = 8 p 9 5 p 8 p = 9 3 p = 9 p = 3

(b)
3 q = 20 13 q 4 12 q = 20 13 q 12 q + 13 q = 20 25 q = 20 q = 4 5