Algebra Calculator
Enter algebraic expressions or simple equations to solve and simplify. This tool helps students and enthusiasts check their work quickly.
Why use our Algebra Calculator? Quickly solve equations, evaluate expressions, and simplify algebraic formulas without manual calculations. Perfect for homework, tutoring, or practice.
Supported Features: Solve linear equations, evaluate expressions, handle powers, and basic arithmetic operations.
Tips: Use standard algebra notation. For example, use `^` for powers, `*` for multiplication, and `=` for equations.
How to Use This Algebra Calculator
This algebra calculator helps you evaluate mathematical expressions and verify your solutions quickly. Follow these steps:
- Enter your expression in the input field using standard notation. Use
*for multiplication,/for division, and^for exponents. - Use parentheses to group terms and control the order of operations, for example
(3+2)*5. - Click "Solve" to evaluate the expression and see the result.
- Check your answer against the displayed solution. If you see an error message, review your expression for invalid characters or syntax.
Understanding Algebra
What Is Algebra?
Algebra is a branch of mathematics that uses letters (called variables) to represent unknown quantities. Instead of working only with specific numbers, algebra lets you write general rules and formulas that apply to many situations. It forms the foundation for nearly all advanced mathematics, from calculus to statistics to computer science.
Variables and Expressions
A variable is a symbol (usually a letter like x, y, or z) that stands for an unknown number. An algebraic expression combines variables, numbers, and operations. For example, 3x + 7 is an expression where x is the variable, 3 is its coefficient, and 7 is a constant term.
Solving Linear Equations
A linear equation is an equation where the highest power of the variable is 1. The general form is ax + b = c. Solving means isolating the variable on one side to find its value. The strategy is to perform the same operation on both sides of the equation to keep it balanced.
Systems of Equations
A system of equations is a set of two or more equations with the same variables. To find a solution, you need to find values that satisfy all equations simultaneously. Common methods include substitution (solve one equation for a variable and plug it into the other) and elimination (add or subtract equations to cancel a variable).
Key Algebra Formulas
Solving a Linear Equation
ax + b = c
ax = c - b
x = (c - b) / a
Quadratic Formula
For any quadratic equation of the form ax^2 + bx + c = 0, the solutions are:
x = (-b +/- sqrt(b^2 - 4ac)) / (2a)
The expression under the square root, b^2 - 4ac, is called the discriminant. If it is positive, there are two real solutions. If it is zero, there is exactly one real solution. If it is negative, there are no real solutions (only complex ones).
Slope-Intercept Form
y = mx + b
m = slope (rise / run)
b = y-intercept (where the line crosses the y-axis)
Worked Example: Solve 3x + 7 = 22
Let us solve the linear equation 3x + 7 = 22 step by step:
Step 1: Write the equation: 3x + 7 = 22
Step 2: Subtract 7 from both sides to isolate the term with x: 3x = 22 - 7 = 15
Step 3: Divide both sides by 3 to solve for x: x = 15 / 3 = 5
Step 4: Verify by substituting back: 3(5) + 7 = 15 + 7 = 22. Correct!
This method -- performing the same operation on both sides to keep the equation balanced -- works for any linear equation of the form ax + b = c.
Algebra Tips and Tricks
- Always simplify first. Before solving, combine like terms and simplify both sides of the equation.
- Check your solution. After finding a value for x, substitute it back into the original equation to verify it works.
- Watch for sign errors. The most common algebra mistake is dropping a negative sign. Be careful when subtracting or distributing negatives.
- Factor when possible. For quadratic equations, try factoring before resorting to the quadratic formula. It is often faster.
- Use inverse operations. Addition undoes subtraction, multiplication undoes division, and vice versa. This is the core principle for isolating variables.
- Graph to understand. Plotting an equation on a coordinate plane can give you a visual understanding of solutions. The x-intercepts of a graph are the solutions.
Common Algebra Identities & Factoring Formulas
These identities appear constantly in algebra, calculus, and physics. Recognizing them instantly speeds up factoring and simplification.
Difference of Squares: a² − b² = (a + b)(a − b)
Example: x² − 9 = (x + 3)(x − 3)
Perfect Square (addition): (a + b)² = a² + 2ab + b²
Example: (x + 5)² = x² + 10x + 25
Perfect Square (subtraction): (a − b)² = a² − 2ab + b²
Example: (x − 4)² = x² − 8x + 16
Sum of Cubes: a³ + b³ = (a + b)(a² − ab + b²)
Difference of Cubes: a³ − b³ = (a − b)(a² + ab + b²)
Linear Equation Forms Quick Reference
| Form | Equation | Best Used When |
|---|---|---|
| Slope-Intercept | y = mx + b | You know slope and y-intercept |
| Point-Slope | y − y₁ = m(x − x₁) | You know slope and one point |
| Standard Form | Ax + By = C | Comparing two equations |