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SAMATICA
In this chapter: Equations and inequalities
  1. Solve a quadratic equation
  2. Solve cubic, quartic and quintic equations, including complex roots
  3. Solve polynomial inequalities of degree 2, 3 and 4
  4. Solve simultaneous linear equations in 2, 3 or 4 unknowns
  5. SOLVE
  6. Factor, expand and simplify algebraic expressions

Factor, expand and simplify algebraic expressions in Scientific calculator plus 991 for Android

Type the expression, press 2nd to open the 2nd keyboard, then FACTOR, EXPAND or SIMPLY. FACTOR turns a polynomial into a product, 1 + 2x + x² into (1 + x)²; EXPAND multiplies out powers and products of sums, (x + y)³ into x³ + 3x²y + 3xy² + y³; SIMPLY rewrites an expression with fewer terms, 2sin(x)² + 2cos(x)² as 2. Letters stay letters throughout.

Keys
2nd, then FACTOR, EXPAND or SIMPLY
Works on
the expression on the input line, letters and all
FACTOR
a polynomial into a product
EXPAND, SIMPLY
multiplied out; fewer terms or operations

Three functions on the 2nd keyboard rewrite an expression instead of working out its value. They take the expression on the input line as it is, letters included, and give back an equivalent one: a product, a sum multiplied out, or a shorter form.

The 2nd keyboard: FACTOR, EXPAND and SIMPLY lead the row under SHIFT and ALPHA.
The 2nd keyboard: FACTOR, EXPAND and SIMPLY lead the row under SHIFT and ALPHA.

Use them

To factor, expand or simplify

  1. Type the expression on the input line. Letters come from ALPHA: x is ALPHA ) x, y is ALPHA S⇌D y, a is ALPHA (-) a.

  2. Press 2nd to open the 2nd keyboard.

  3. x⁴ − 1 factored: (−1 + x)(1 + x)(1 + x²).

    Press FACTOR, EXPAND or SIMPLY. The rewritten expression appears as the answer.

Factor

2nd FACTOR factors a polynomial into a product of simpler expressions.

A perfect square

in 1 + 2x + x²

out (1 + x)²

Three factors

in x⁴ - 1

out (-1 + x)(1 + x)(1 + x²)

FACTOR rewrites a polynomial; it does not solve it. For the roots, give the same expression to SOLVE, which solves an expression on its own against 0.

Expand

2nd EXPAND expands positive powers and products of sums into a fully multiplied-out expression.

A cube, multiplied out

in (x + y)³

out x³ + 3x²y + 3xy² + y³

Two sums multiplied

in (a + b)(a + c + d)

out a² + ab + ac + bc + ad + bd

Simplify

2nd SIMPLY rewrites an expression in an equivalent form with fewer terms or operations. It is not only algebra: it knows trigonometric identities as well.

A common factor collected

in ax² + bx²

out (a + b)x²

A trigonometric identity

in 2Sin(x)² + 2Cos(x)²

out 2

sin(x)² + cos(x)² is 1 for every x, so twice it is 2.

At a glance

KeysWhat they do
2nd FACTORFactors a polynomial into a product
2nd EXPANDMultiplies out powers and products of sums
2nd SIMPLYRewrites the expression with fewer terms or operations
SHIFT CALC SOLVEFinds the roots instead, on the SOLVE page

Questions

How do I factorise a polynomial on the calculator?

Type it on the input line, press 2nd, then FACTOR. x⁴ − 1 comes back as (−1 + x)(1 + x)(1 + x²), and 1 + 2x + x² as (1 + x)². FACTOR rewrites the polynomial; for its roots, give the same expression to SOLVE.

Can it expand brackets with letters in them?

Yes. EXPAND on the 2nd keyboard multiplies out powers and products of sums whatever letters they hold: (a + b)(a + c + d) comes back as a² + ab + ac + bc + ad + bd.

What is the difference between SIMPLY and FACTOR?

FACTOR writes a polynomial as a product of simpler factors. SIMPLY looks for any equivalent form with fewer terms or operations, and knows identities such as sin² + cos² = 1: 2sin(x)² + 2cos(x)² comes back as 2, and ax² + bx² as (a + b)x².

Related pages

Written from the calculator's own manual and from the app itself, version 7.6.0; every figure is one the manual shows or a capture of the app proves. Last revised on 26 September 2026.

Bug reports and feature requests go to kimcuc@samatica.com — a person reads it.