Definitions [3]
Definition: Variables
A variable is a symbol, usually a letter (like x, y, or z), representing an unknown or changeable numerical value in an equation or an algebraic expression.
Definition: Constants
A constant is a fixed value that does not change.
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Examples: 5, −7, 256
A balanced equation is one in which the value of the left-hand side (LHS) is equal to the value of the right-hand side (RHS).

Key Points
Key Points: Equations Reducible to Linear Equations
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Some equations are not linear in the given variables.
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By a suitable change of variables, they can be reduced to linear equations.
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After substitution, the equations become linear in the new variables.
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Denominators must not be zero.
Concepts [10]
- Constants and Variables in Mathematics
- Equation in Mathematics
- Expressions with Variables
- Word Problems on Linear Equations
- Solving Equations Which Have Linear Expressions on One Side and Numbers on the Other Side
- Some Applications Solving Equations Which Have Linear Expressions on One Side and Numbers on the Other Side
- Solving Equations Having the Variable on Both Sides
- Some More Applications on the Basis of Solving Equations Having the Variable on Both Sides
- Reducing Equations to Simpler Form
- Equations Reducible to Linear Equations
