2. what is the missing number
pattern 1, 3, 9, -, 81?

The missing number is 27

Step-by-step explanation:It is a matter of spotting the relationship if you can. If not obvious you will need to experiment to find what type of sequence it is; geometric or arithmetic.

Observe that there is a connection of 3 in the numbers 1,3,9 in that

1

×

3

=

3

Lets experiment with that for a moment!

If we apply the same rule to 3 what will we get?

3

×

3

=

9

which is correct.

Ok. lets apply the same rule yet again!

9

×

3

=

27

Using 27, if we apply the rule once more and get 81 we have found the correct 'rule' for this sequence.

27

×

3

=

81

'

This works so the missing number is 27

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below:

correct answer:

b.(19,-2)