SAT Subject Test Mathematics Level 2

(ax)(bx) = (ab)x^2

Multiplying Binomials—FOIL

Classic Factorables

Factor common to all terms:

ax  +   ay  =   a(x +   y)

Difference of squares:

a^2     −   b^2     =   (a  −   b)(a    +   b)

Square of binomial:

a^2     +   2ab +   b^2     =   (a  +   b)^2

Quadratic Formula

If ax^2 + bx + c = 0, then .

Inequalities and Absolute Value

For all n > 0,

(a  +   b)(c    +   d)  =   ?

First   =   ac

Outer   =   ad

Inner   =   bc

Last    =   bd

Product =   ac  +   ad  +   bc  +   bd