Linear Equation Solver
Enter the coefficients for ax + b = c to solve for x.
Last updated: September 5, 2026
Frequently asked questions
How do I solve a linear equation like 3x + 5 = 20?
Isolate x: subtract 5 from both sides to get 3x = 15, then divide both sides by 3 to get x = 5. In general, for ax + b = c, x = (c − b) / a.
What if the equation has x on both sides, like 2x + 3 = x + 10?
Move all the x terms to one side and constants to the other first: subtracting x from both sides gives x + 3 = 10, then subtracting 3 gives x = 7. Rearrange your equation into the ax + b = c form before entering it here.
What does it mean if a = 0 in this calculator?
If a is 0, there's no x term left to solve for - the equation becomes just b = c. If that's true (like 5 = 5), every value of x satisfies it; if it's false (like 5 = 7), no value of x can, since the x term can't change the outcome.
Can this solve equations where x has a fractional or decimal coefficient?
Yes - a doesn't need to be a whole number. For example, 0.5x + 5 = 20 solves the same way: x = (20 − 5) / 0.5 = 30.
What's the solution to 3x + 5 = 20?
x = 5 - using x = (c − b)/a: x = (20 − 5)/3 = 15/3 = 5.
Is a 'linear equation' the same as an 'algebraic equation'?
Not quite - a linear equation specifically means the variable appears only to the first power (no x², √x, or 1/x terms), making its graph a straight line. 'Algebraic equation' is a broader term that includes linear, quadratic, and higher-degree equations.