Positive Numbers are to the right of the number line.
Answer:
The length of EF = x = 18 cm
Option A is correct.
Step-by-step explanation:
Ware given perimeter of triangle = 97 cm
We need to find length of EF = x = ?
The length of EG = x+7
The length of EF = x
The length of GF = 3x
The formula used is: 
Putting values and finding x i.e length of EF

So, value of x=18 cm
The length of EF = x = 18 cm
Option A is correct.
Answer:
Option c
or 
Step-by-step explanation:
The absolute value is a function that transforms any value x into a positive number.
Therefore, for the function
x> 0 for all real numbers.
Then the inequation:
has two cases
if
(i)
if
(ii)
We solve the case (i)

We solve the case (ii)

Then the solution is:
or 
Sum of interior angles=(n-2)180
3060=(n-2)180
3060/180=n-2
17=n-2
n=17+2
n=19..