Question

How do you solve \[3\left( x-4 \right)=15\]?

Answer 1

Hint: In this problem we have to solve the given equation \[3\left( x-4 \right)=15\] and find the value of x. We can solve this problem in a simple way, that is we can divide by 3 on both sides of the equation and we can add 4 on both sides of the resulted equation to get the value of x. we can also multiply the number 3 inside the brackets and proceed the steps to get the value of x.

Complete step by step answer:
We know that the given equation is,
\[3\left( x-4 \right)=15\]…… (1)
Now, we can divide by 3 on both sides of the equation (1), we get
\[\Rightarrow \dfrac{3\left( x-4 \right)}{3}=\dfrac{15}{3}\]
Now, we can cancel the similar terms, we get
\[\Rightarrow \left( x-4 \right)=5\]
Now we can add 4 on both sides, we get
\[\Rightarrow x-4+4=5+4\]
We can now cancel the similar, terms with opposite sign, we get
\[\Rightarrow x=9\]

Therefore, on solving \[3\left( x-4 \right)=15\], the value of x is 9.

Note: We can also solve this problem in another method.
We know that the given equation is,
\[3\left( x-4 \right)=15\]…… (1)
We can multiply 3 inside the bracket, we get
\[\begin{align}
  & \Rightarrow 3x-3\left( 4 \right)=15 \\
 & \Rightarrow 3x-12=15 \\
\end{align}\]
We can now add 12 on both sides, we get
\[\begin{align}
  & \Rightarrow 3x-12+12=15+12 \\
 & \Rightarrow 3x=27 \\
\end{align}\]
Now, we can divide by 3 on both sides we get,
\[\begin{align}
  & \Rightarrow \dfrac{3x}{3}=\dfrac{27}{3} \\
 & \Rightarrow x=9 \\
\end{align}\]