Answer:
1.5
18 and 33
Step-by-step explanation:2.
c
Answer:
22, 19, 16 and - 5
Step-by-step explanation:
To evaluate any term from the n th term formula substitute the terms position value for n
given 
= 25 - 3n, then
(a)
= 25 - (3 × 1) = 25 - 3 = 22
= 25 - (3 × 2) = 25 - 6 = 19
= 25 - (3 × 3) = 25 - 9 = 16
(b)
= 25 - (3 × 10) = 25 - 30 = - 5
This involves quite a lot of arithmetic to do manually.
The first thing you do is to make the first number in row 2 = to 0.
This is done by R2 = -3/2 R1 + R2
so the matrix becomes
( 2 1 1) ( -3 )
( 0 -13/2 3/2) (1/2 )
(5 -1 2) (-2)
Next step is to make the 5 in row 5 = 0
then the -1 must become zero
You aim for the form
( 1 0 0) (x)
(0 1 0) (y)
(0 0 1) ( z)
x , y and z will be the required solutions.
