Question

Write the equation for the following statement, 'when a number is squared and 3 times of that number is added to it, it gives 18."

Answer 1

To write an equation from this statement, We'll have to consider following condition.
   Let the given number is 'x'.
A/q,
         x²+x+x+x = 18
or,     x²+3x-18 = 0
This is the equation of given statement.

Answer 2

assume the number the n.
when a number is squared(n²) and 3 times of that number(3n) is added to it, it gives 18 or
n² + 3n = 18
or n² + 3n - 18 = 0.