To solve an equation, you are looking at finding the value of the letter. Your goal is to end up with \(x = \text{ something}\)
Solve with an addition
\[x+5=12\]
The inverse (or opposite) of \(+5\) is \(-5\). We must do this to both sides though.
\[x+5-5=12-5\]
\[x=7\]
Solve with a subtraction
\[x-7=10\]
The inverse (or opposite) of \(-7\) is \(+7\).
\[x-7+7=10+7\]
\[x=17\]
Solve with a multiplication
\[8x=40\]
\(8x\) means \(8 \times x\). The inverse (or opposite) of \(\times 8\) is \(\div 8\).
\[8x\div 8=40\div 8\]
\[x=5\]
Solve with a division
\[\frac{x}{3}=20\]
\(\dfrac{x}{3}\) means \(x \div 3\). The inverse (or opposite) of \(\div 3\) is \(\times 3\).
\[\frac{x}{3}\times 3=20\times 3\]
\[x=60\]