Question

How do you solve $x+5=18$?

Answer 1

Hint: In this problem we need to solve the given equation i.e., we need to calculate the value of $x$ for which that value satisfies the given equation. To solve any equation, we will simply apply reverse arithmetic operation for the arithmetic operation which is involved in the given equation. So, we will first observe the given equation and list the arithmetic operations which are involved in the given equation. Now we will apply reverse arithmetic operation for the operation which is the given equation and we will simplify the obtained equation to get the required result.

Complete step-by-step solution:
Given equation, $x+5=18$.
Observing the given equation, we can see that the number $5$ is adding to the variable $x$ in the above equation.
To solve the above equation applying the reverse arithmetic operation for addition which is subtraction for the above equation. Hence subtracting the number $5$ from the both sides of the above equation, then we will get
$x+5-5=18-5$
We know that $+a-a=0$, then the above is modified as
$x=18-5$
We have the value $18-5=13$, then we will get
$\therefore x=13$
Hence the solution for the equation $x+5=18$ is $x=13$.

Note: We can also check whether the obtained solution is correct or not by substituting the calculated $x$ in the given equation. Then we will get
$\begin{align}
  & x+5=18 \\
 & \Rightarrow 13+5=18 \\
 & \Rightarrow 18=18 \\
 & \Rightarrow LHS=RHS \\
\end{align}$
Hence the calculated result is correct.