Question

How do you solve $10 + 3\left( {x + 2} \right) = 31$ ?

Answer 1

Hint: A mathematical equation which represents the relationship of two expressions on either
side of the sign. It mostly has one variable and equal to symbol. Simplify each side of the equation by
removing parentheses and combining like terms.
Use addition or subtraction to isolate the variable term on one side of the equation.
Use multiplication or division to solve for the variable.

Complete step-by-step solution:
The given equation is
$ \Rightarrow 10 + 3\left( {x + 2} \right) = 31$
First simplify the term by multiplying the second term in side brackets, we get
$ \Rightarrow 10 + 3x + 6 = 31$
Now add $10$ and $6$, we get
$ \Rightarrow 3x + 16 = 31$
Move all terms not containing $x$ to the RHS
$ \Rightarrow 3x = 31 - 16$
When we subtract the terms in RHS, we get
$ \Rightarrow 3x = 15$
Now bring $3$ to the RHS, we get
$ \Rightarrow x = \dfrac{{15}}{3}$
When we divide the above term, we get
$ \Rightarrow x = 5$

Therefore, by solving the equation $10 + 3\left( {x + 2} \right) = 31$ we get $x = 5$

Note: When solving a simple equation, think of the equation as a balance, with the equals sign $\left( = \right)$ being the Fulcrum or center. Thus, if you do something to one side of the equation, you must do the same thing to the other side. Doing the same thing to both sides of the equation (say, adding $2$ to each side) keeps the equation balanced.
Solving an equation is the process of getting what you're looking for, or solving for, on one side of the equals sign and everything else on the other side. You're really sorting information. If you're solving for $x$ , you must get $x$ on one side by itself. In fact, solving an equation is just like solving a puzzle. And like puzzles, there are things you can (and cannot) do. Here are some things you can do.
Add or subtract the same value from both sides. Clear out any fractions by multiplying every term by the bottom parts Divide every term by the same nonzero value
Combine Like Terms
Factoring
Expanding (the opposite of factoring) may also help
Recognizing a pattern, such as the difference of squares
Sometimes we can apply a function to both sides (e.g. square both sides)