Sunday, May 12, 2013

GRE Math formula sheet : Algebra

By Revised GRE on 2:16 AM


Algebra


Simplifying Expressions


Simplifying expressions:


Multiplying monomials:

Multiplying polynomials using FOIL (First, Outer, Inner, Last)


Factoring

Factoring using Greatest Common Factors:


Factoring using difference of squares:


Factoring using quadratic polynomials:



Combining methods:


Factoring rational expressions (as long as x is not equal to 4):

Solving Equations

The golden rule of solving equations is, “What you do to one side of an equation, you must also do to the other”.

Eliminating fractions:


Multiply by the LCD:


Cross-multiplication:


Quadratic equations:


 Quadratic formula:

Two variables/systems of equations 



Method 1: Substitution



Method 2: Elimination


A system of two equations with two unknowns can have 0, 1, or infinitely many solutions.

To solve a system of three equations with three variables, use substitution to reduce the problem to two equations with two variables, and solve from there.