Math Solver Calculator

Solve linear equations, quadratic equations, and systems of two equations with step-by-step explanations.

ax + b = c

Solution for x

5

From 3x + 7 = 22

Equation type

Linear

First-degree equation with one unknown variable.

Verification

22

3(5) + 7 should equal 22

Step-by-step solution

  1. Start: 3x + 7 = 22
  2. Subtract 7: 3x = 15
  3. Divide by 3: x = 5

Share your results

Tweet

Understanding the calculator

How it works

A math solver calculator is useful because algebra is the part of math where most people get stuck. The mechanics of isolating a variable, applying the quadratic formula, or solving simultaneous equations are straightforward in theory but easy to mess up in practice. A solver that shows step-by-step workings is more valuable than one that just prints an answer, because users can verify where they went wrong and learn the process.

This solver handles three equation types. Linear equations of the form ax + b = c are solved by isolating x through subtraction and division. Quadratic equations use the quadratic formula with discriminant analysis to determine whether roots are real, repeated, or complex. Systems of two linear equations are solved with Cramer's rule using 2x2 determinants.

The math behind it

Key formulas

Linear: x = (c - b) / a

For 3x + 7 = 22: x = (22 - 7) / 3 = 5. Subtract the constant, divide by the coefficient.

Quadratic: x = (-b +/- sqrt(b² - 4ac)) / 2a

For x² + 5x + 6 = 0: discriminant = 25 - 24 = 1. x = (-5 +/- 1) / 2 = -2 or -3.

Cramer's Rule: x = Dx/D, y = Dy/D

For the system 2x + 3y = 8, x - y = 1: D = -5, Dx = -11, Dy = -6. x = 2.2, y = 1.2.

Real-world scenarios

Practical examples

01

Solving a word problem: "Three times a number plus 7 equals 22"

Equation: 3x + 7 = 22. Step 1: subtract 7 from both sides: 3x = 15. Step 2: divide by 3: x = 5.

02

Finding when a projectile hits the ground

Height equation: -16t² + 48t + 5 = 0. Using the quadratic formula: t = (-48 +/- sqrt(2304 + 320)) / -32. The positive root gives the time of impact.

03

Two equations, two unknowns from a mixing problem

A store sells pens ($2) and notebooks ($5). Total items: 12. Total cost: $39. System: x + y = 12, 2x + 5y = 39. Solution: 7 pens and 5 notebooks.

Getting the most value

When to use this calculator

Use a math solver when you need to verify algebraic work, check homework answers, or solve equations that appear in real-world problems. The step-by-step output is especially valuable for learning — it shows not just the answer but the method.

Quadratic equations appear in physics (projectile motion), engineering (optimization), finance (break-even analysis), and many other fields. Having a solver with discriminant analysis saves time and reduces errors.

Systems of equations arise whenever two constraints must be satisfied simultaneously — mixing problems, supply and demand, budget allocation, and geometric intersection problems.

Expert guidance

Tips and best practices

  • Always check your answer by substituting it back into the original equation. This catches sign errors and arithmetic mistakes.
  • A negative discriminant in a quadratic means the equation has complex (imaginary) roots. In real-world applications, this usually means no physical solution exists.
  • When setting up systems of equations from word problems, define your variables clearly first, then translate each constraint into an equation.
  • Cramer's rule fails when the determinant is zero, which means the system has either no solution (parallel lines) or infinitely many solutions (same line).

Summary

Key takeaways

  • Linear equations are solved by isolating the variable through inverse operations (subtract, then divide).
  • The quadratic formula works for any quadratic equation, and the discriminant reveals the nature of the solutions.
  • Systems of two linear equations can be solved with Cramer's rule, substitution, or elimination — each method has advantages depending on the problem.
  • Step-by-step solutions are more valuable than bare answers because they enable learning and error-checking.
  • Always verify solutions by substituting back into the original equation.

Common questions

Frequently asked questions

What types of equations can this solve?

Linear equations of the form ax + b = c, quadratic equations of the form ax² + bx + c = 0, and systems of two linear equations with two unknowns.

What is the discriminant in a quadratic equation?

The discriminant is b² − 4ac. It determines the nature of the roots: positive means two real roots, zero means one repeated root, and negative means two complex roots.

How does the system solver work?

It uses Cramer's rule, which relies on determinants to find the unique intersection point of two lines. If the determinant is zero, the lines are parallel or identical.

Related calculators