Important concepts for GMAT Mathematics - Part 1

Numbers

Fractions to decimals

Powers of Numbers

Other Numbers

Arithmetic

Order of operations

Fractions

Adding Fractions
Subtracting Fractions
Multiplying Fractions
Dividing Fractions
Dividing Exponents
Multiplying small numbers

ALGEBRA

Simultaneous equations
The first step is to try to eliminate one of the unknowns. Here is an example of solving by substitution. Using Equation 1 to write y in terms of x gives y = 7 - 3x. Plugging into equation 2 gives 3x - 2(7 - 3x) = 13. Solving x yields x = 3. Plugging in the expression for y gives y = -2.

One equation with two unknowns
Two unknowns can sometimes be solved in one equation under certain constraints. We get the same equation 9x + 5y = 52. Be aware of that implicit assumption that x and y are positive integers.

Three Important Algebra Patterns What is the strategy for formula problems with unspecified amounts?
Ex: "The speed of the rocket was increased a certain amount.."
Pick smart (easy-to-work-with) numbers! (formula: change/original = %change)

What is the equation for linear sequences?
Sn = k(n) + x
Where k is the constant difference between successive terms.
x is the constant that determines S1 (must be solved for)



GMAT