Variable equations are mathematical statements that contain an equals sign and at least one variable. A variable is a symbol, usually a letter, that represents an unknown value.
Think of a variable as a mystery number waiting to be discovered. Your job is to find which number makes the equation true.
To evaluate a variable equation means to find the value of the variable that makes the equation true. You do this by performing inverse operations to isolate the variable.
Always perform the same operation on both sides of the equals sign to keep the equation balanced, just like a scale.
When a variable has a number added to it, subtract that number from both sides. When a variable has a number subtracted from it, add that number to both sides.
Addition and subtraction are inverse operations - they undo each other.
When a variable is multiplied by a number, divide both sides by that number. When a variable is divided by a number, multiply both sides by that number.
Multiplication and division are inverse operations - they undo each other.
Some equations require two steps to solve. First, undo addition or subtraction, then undo multiplication or division.
Think of the equation like getting dressed: the last operation put on is the first one you take off when solving.
Some equations contain two variables. When you know the value of one variable, you can substitute it into the equation to find the value of the other variable.
When substituting values, replace the variable with the given number and perform the calculation carefully. Always double-check your arithmetic.
Always verify your answer by substituting it back into the original equation to ensure both sides are equal.
Checking your work helps catch calculation errors and confirms your solution is correct.