Substitute Into Formula Calculator

Work out substitute into formula instantly with clear inputs, formula shown and shareable results.

About Substitute Into Formula Calculator

Substitution replaces the variable with a number and then evaluates, respecting the order of operations: powers first, then multiplication, then addition.

Formula

Substitution

value = a·x² + b·x + c evaluated at the given x

Worked example

With the default values below, Substitute Into Formula Calculator returns Value of the expression of 15.00000000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Coefficient a in ax² + bx + c: 2
Coefficient b: -5
Constant c: 3
Substitute x =: 4

Results

Value of the expression: 15.00000000
ax² contribution: 32.00000000
bx contribution: -20.00000000
Expression used: 2x^2 - 5x + 3

Step by step

1Values used
2Substitution
3Value of the expression= 15.00000000
4ax² contribution= 32.00000000
5bx contribution= -20.00000000
6Expression used= 2x^2 - 5x + 3

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 8 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Evaluate 2x² − 5x + 3 at x = 4.

2 × 16 − 20 + 3 = 32 − 20 + 3 = 15.

What about negative x?

Square first, so x² stays positive. At x = −4 the result is 32 + 20 + 3 = 55.