The certain number in this word problem is 25.
- Let the certain number be N.
In this exercise, you're required to write a mathematical (algebraic) expression and then use it solve for the unknown variable, which is the certain number N.
Translating the word problem into an algebraic expression, we have;
[tex]18 + 6N = 168[/tex]
Rearranging the equation (collecting like terms), we have;
[tex]6N = 168 - 18\\\\6N = 150\\\\N = \frac{150}{6}[/tex]
Certain number, N = 25
Therefore, the certain number is 25.
Find more information: https://brainly.com/question/596290
