Question

Solve for $x:$
$7x-1=13$

• A. $x=2$
• B. $x=1$
• C. $x=3$
• D. $x=4$

Answer 1

The correct option is A $x=2$

Given, the equation is $7x-1=13.$

Isolate the variable and solve the equation.
To isolate the variable, we need to perform some operations that two operations undo each other.
$\Rightarrow$ Addition and subtraction undoes each other
$\Rightarrow$ Multiplication and division undoes each other

In the given equation, 1 is subtracted on left hand side of the equation. So we need to undo the subtraction operation by adding 1 to both sides of the equation.
$\Rightarrow 7x-1=13$
$+1=+1$
$--------$
$7x=14$
$\Rightarrow 7x=13+1$
$\Rightarrow 7x=14$

In the given equation, 7 is multiplied on left hand side of the equation. So we need to undo the multiplication operation by dividing 7 on both sides of the equation.
$\Rightarrow \frac{7x}{7}=\frac{14}{7}\Rightarrow x=2$

Hence, solution of the equation $7x-1=13$ is $x=2.$