FOIL Calculator
Calculate foil instantly in your browser.
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What this tool does
Calculate foil instantly in your browser. FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
How to use the FOIL Calculator
- Enter or select first term coefficient a.
- Enter or select first constant b.
- Enter or select second term coefficient c.
- Enter or select second constant d.
- Read the calculated result; change any measurement to compare alternatives.
Formula
FOIL multiplies (ax + b)(cx + d) term by term: First acx², Outer adx, Inner bcx, Last bd — then the Outer and Inner terms combine into (ad + bc)x.
- a
- First term coefficient a
- b
- First constant b
- c
- Second term coefficient c
- d
- Second constant d
FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
Worked example
For foil calculator, the following measurements illustrate the exact method: First term coefficient a: 2; First constant b: 3; Second term coefficient c: 1; Second constant d: 4.
Inputs
- First term coefficient a2
- First constant b3
- Second term coefficient c1
- Second constant d4
Result
- Expanded form2x² + 11x + 12
- x² coefficient (First)2
- x coefficient (Outer + Inner)11
- Constant (Last)12
Results explained
- Expanded form
- Expanded form from the formula above. FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
- x² coefficient (First)
- x² coefficient (First) from the formula above. FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
- x coefficient (Outer + Inner)
- x coefficient (Outer + Inner) from the formula above. FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
- Constant (Last)
- Constant (Last) from the formula above. FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
Frequently asked questions
FOIL multiplies (ax + b)(cx + d) term by term: First acx², Outer adx, Inner bcx, Last bd — then the Outer and Inner terms combine into (ad + bc)x.
FOIL is just the distributive law organized for two binomials; it works for any real coefficients, including negatives and zeros.
Where mathematically meaningful, yes. Fields specify permitted ranges and undefined operations display an error.
Exact integer calculations use safe integers; decimal calculations use browser floating point, so small rounding differences can occur.
All values remain in your browser and are never uploaded.