Question

How do you solve $ 3x - 1 = 9? $

Answer 1

Hint: In this problem we have given an equation. And we asked to solve the equation. Here the given equation contains a variable and we don’t know the value of the variable. So, our aim is to find the value of the variable which is present in the given equation. So by finding the value of the variable which is present in the given equation we can easily solve this problem.

Complete step-by-step solution:
The given equation is $ 3x - 1 = 9 $
So our given equation contains only one variable which is $ x $ and we have to find the value of $ x $ .
First let us add $ 1 $ to both sides of the given equation, we get
 $ \Rightarrow 3x - 1 + 1 = 9 + 1 $
 $ \Rightarrow 3x + 0 = 9 + 1 $ , if we add $ + 1 $ and $ - 1 $ then the value becomes zero
Next we add the numbers of right hand side and it becomes
 $ 3x = 10 $ , if we add any number with zero means we get the same number.
Now let us divide both sides of the equation by the same term and the term is the coefficient of $ x $ . we get,
 $ \Rightarrow \dfrac{{3x}}{3} = \dfrac{{10}}{3} $
Cancel the common terms that are in both the numerator and denominator of the left hand side. We get,
 $ \Rightarrow x = \dfrac{{10}}{3} $

Therefore, the value of the variable $ x $ is $ \dfrac{{10}}{3} $ .

Note: While solving the given types of equations we do not confuse the solution $ x = 0 $ with no solution. The solution $ x = 0 $ means that the value $ 0 $ satisfies the equation, so there is a solution.
When we solve this equation we have to be very careful about the signs of numbers. When we take a number with negative sign to another side of equal to symbol it will become positive and vice versa.