Math
Algebra Calculator
Solve linear and quadratic equations with step-by-step solutions.
Linear Equation
ax + b = c?x + ? = ?
Solution
x = ?
—
Quadratic Equation
ax²+bx+c=0?x² + ?x + ? = 0
Discriminant (Δ = b²−4ac)
—
—
x₁
—
x₂
—
—
Quadratic Formula
x = (−b ± √(b²−4ac)) / 2a
Δ > 0
Two distinct real roots
Δ = 0
One repeated real root
Δ < 0
Two complex conjugate roots
Vieta's Formulas
For ax² + bx + c = 0 with roots x₁, x₂:
Algebraic Identities
Completing the Square
Alternative method for ax² + bx + c = 0:
1. x² + (b/a)x = −c/a
2. add (b/2a)² to both sides
3. (x + b/2a)² = (b²−4ac) / 4a²
4. x = −b/2a ± √(b²−4ac) / 2a
FAQ
Frequently asked questions.
What calculator should I use for algebra?
For solving algebra problems online, a dedicated algebra calculator like those found on MathPapa, Symbolab, or Mathway is the best choice. These tools accept typed expressions and equations, then return step-by-step solutions. Unlike a basic scientific calculator, an online algebra calculator can handle variables, simplify expressions, factor polynomials, and solve systems of equations.
How do I do algebra on a calculator?
Rewrite your equation in the form ax + b = c (linear) or ax² + bx + c = 0 (quadratic), then enter the coefficients. For example, 3x + 2 = 14 is a = 3, b = 2, c = 14, which gives x = 4. The calculator returns the solution along with a step-by-step breakdown. Some other tools also accept typed expressions, inequalities, and systems of equations; this one focuses on linear and quadratic equations.
How is algebra calculated?
Algebra is solved by isolating the unknown variable through a sequence of inverse operations — addition, subtraction, multiplication, and division applied to both sides of the equation equally. For quadratic equations, methods such as factoring, completing the square, or the quadratic formula are used. An online algebra calculator automates these steps and shows each transformation so you can follow the logic.
Can my TI-84 do algebra?
Yes, the TI-84 graphing calculator includes a built-in Equation Solver that can find numerical solutions for algebraic equations. It supports graphing functions, building t-charts, solving systems of equations, and evaluating expressions — making it widely used in college algebra courses. However, an online algebra calculator offers more convenience with instant access, symbolic step-by-step solutions, and no hardware required.
Can I solve quadratic equations with this algebra calculator?
Yes, this algebra calculator supports quadratic equations of the form ax² + bx + c = 0. Enter the coefficients a, b and c and the calculator applies the quadratic formula, returning both roots along with the discriminant and a step-by-step solution. Both real and complex (imaginary) roots are handled.
Does the algebra calculator show its work?
Yes, the calculator shows the steps for every linear and quadratic equation, not just the final answer. For linear equations it shows how x is isolated; for quadratics it shows the formula, the discriminant and each root. This makes it useful for checking homework and learning the method.
Can I use the algebra calculator to simplify expressions?
No. This calculator solves linear equations (ax + b = c) and quadratic equations (ax² + bx + c = 0); it does not simplify or factor expressions. To simplify by hand, combine like terms (3x + 5x = 8x), expand brackets (2(x + 3) = 2x + 6) and reduce common factors. If your simplified result is an equation you want solved, enter its coefficients here.
How do I solve one-step, two-step and multi-step equations with this calculator?
Every one-step, two-step and multi-step equation reduces to the form ax + b = c, which is what the linear solver takes. One-step: x + 7 = 12 is a = 1, b = 7, c = 12, so x = 5. Two-step: 2x + 3 = 11 gives x = 4. Multi-step: first collect terms, so 5x + 2 = 3x + 10 becomes 2x − 8 = 0 (a = 2, b = −8, c = 0) and x = 4. The letter does not matter: to solve −11b + 33 = 44, enter a = −11, b = 33, c = 44 and you get b = −1.
How do I solve a quadratic that is not already set equal to zero, like x² + 5x − 61 = 8x − 7?
Move every term to one side so the right side is 0. Subtracting 8x and adding 7 gives x² − 3x − 54 = 0, so a = 1, b = −3, c = −54. The discriminant is (−3)² − 4(1)(−54) = 9 + 216 = 225, its square root is 15, and x = (3 ± 15) / 2, which gives x = 9 and x = −6. Check: 9² + 5(9) − 61 = 65 and 8(9) − 7 = 65.
How do I solve quadratics with irrational roots, like 3m² + 11m + 9 = 0 or 4n² − 19n + 18 = 0?
Enter a, b and c and read the roots from the result; they appear as decimals. For 3m² + 11m + 9 = 0 the discriminant is 121 − 108 = 13, so m = (−11 ± √13) / 6, about −1.2324 and −2.4343. For 4n² − 19n + 18 = 0 the discriminant is 361 − 288 = 73, so n = (19 ± √73) / 8, about 3.4430 and 1.3070. A positive discriminant that is not a perfect square means the roots are irrational and the equation does not factor over whole numbers.
How do I solve an equation with a fraction, like (6/7)z + 15 = 93?
Multiply every term by the denominator to clear the fraction. Multiplying by 7 gives 6z + 105 = 651, so a = 6, b = 105, c = 651 and z = (651 − 105) / 6 = 91. Check: (6/7)(91) + 15 = 78 + 15 = 93.
How do I solve an absolute value equation like |15 + b| = 9?
Split it into two linear equations, one with +9 and one with −9, and solve each. 15 + b = 9 gives b = −6 (a = 1, b = 15, c = 9 in the calculator). 15 + b = −9 gives b = −24 (c = −9). Check: |15 − 6| = 9 and |15 − 24| = 9. If the right side is negative, as in |x| = −3, there is no solution.
How do I solve for a letter in a formula, like ub = j + r or 5yb = d²b + m?
This calculator takes numbers, so for letters use the same inverse-operation method by hand. ub = j + r: divide both sides by u, so b = (j + r) / u. h = 5nb − xb: factor out b to get h = b(5n − x), so b = h / (5n − x). 5yb = d²b + m: subtract d²b from both sides to get b(5y − d²) = m, so b = m / (5y − d²). b/y − m = d²: add m, then multiply by y, so b = y(d² + m). Once you substitute numbers for the other letters, you can check the answer here.
How do I solve equations with no x term or a common factor, like b² = 0.64, 18x² − 98 = 0 or 15x³ − 55x² + 40x = 0?
b² = 0.64 is a quadratic with no middle term: enter a = 1, b = 0, c = −0.64 to get b = ±0.8. Likewise 18x² − 98 = 0 is a = 18, b = 0, c = −98, giving x = ±7/3 (about ±2.3333). For 15x³ − 55x² + 40x = 0, factor out 5x first: 5x(3x² − 11x + 8) = 0, so x = 0 or 3x² − 11x + 8 = 0. Enter a = 3, b = −11, c = 8: the discriminant is 121 − 96 = 25, so x = (11 ± 5) / 6 = 8/3 or 1. The three solutions are x = 0, 1 and 8/3.
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Last updated: October 8, 2026