PSAT Math Review
Kaplan Method for Math - Correct Answers-Step 1: Read the question, identifying and
organizing important information as you go
Step 2: Chosen the best strategy to answer the question
Step 3: Check that you answered the right question
Slope Equation - Correct Answers-slope = rise/run
Slopes of Lines Parallel to Y-Axis - Correct Answers-m = Undefined, as the lines exist but can't be
numerically calculated
Slopes of Lines Parallel to X-Axis - Correct Answers-m = 0
Y-Intercept Definition - Correct Answers-The value where the model begins
What are linear equations are well-suited for... - Correct Answers-solving for a single variable in
terms of another that is clearly defined
Systems of Equations Definition - Correct Answers-Set of multiple equations with multiple
variables that are interdependent
Useful for modeling and simulaion
When the systems of equations gives an answer like 6=6 or 4=4, then the equations are... -
Correct Answers-Dependent, meaning the system has an infinite amount of solutions
When your system has no solution, it will graph as... - Correct Answers-Two parallel lines
When your system has one solution, it will graph as... - Correct Answers-Two lines that intersect
at a single point
When your system has infinite solutions, it will graph as... - Correct Answers-Two lines that
overlap, making one
Ways to solve Systems of Equations - Correct Answers-Substitution
Combination
Substitution Definition - Correct Answers-Solve the simpler of the two equations for one
, variable and then substitute the result into the other variable
r = 2x + 6
3r + 2x = 18
6x + 18 + 2x = 18
Combination Definition - Correct Answers-Adding the two equations together to eliminate a
variable
-5x + 7y = 39
5x + 9y = 1
16y = 40
Rates Formula - Correct Answers-Distance/work/result = rate * time`
Be sure to remember what units you're working in when doing this!
The conversions from feet to yards and square feet to square feet to square yards are... -
Correct Answers-Not the same!
Square feet * 1/3 * 1/3 = Square Yards
Ratios Definition - Correct Answers-Comparison of one quantity to another
Can compare a part to a part or a part to a whole
Combining Ratios - Correct Answers-To combine a:b and b:c, make b a common value to create
a:c
2:3 and 5:6, 10:15 and 15:18, 10:18
Proportion - Correct Answers-Two ratios set equal to each other
Check the units of each ratios and double-check your work by cross-multiplying
If a/b = c/d, then ad=bc, therefore b/a = d/a but not a/d=b/c
Percent Formula - Correct Answers-Percent = part/whole * 100%
Percent Change Formula - Correct Answers-Percent increase or decrease = (amount of increase
or decrease/original amount) * 100%
What's one thing that you need to be careful of when doing probabilities? - Correct Answers-
Don't just add two percentages together, provided you're not doing P(AuB) problems.
Anatomy of Exponents - Correct Answers-Made up of a base (the larger number) and an
exponent/power
Kaplan Method for Math - Correct Answers-Step 1: Read the question, identifying and
organizing important information as you go
Step 2: Chosen the best strategy to answer the question
Step 3: Check that you answered the right question
Slope Equation - Correct Answers-slope = rise/run
Slopes of Lines Parallel to Y-Axis - Correct Answers-m = Undefined, as the lines exist but can't be
numerically calculated
Slopes of Lines Parallel to X-Axis - Correct Answers-m = 0
Y-Intercept Definition - Correct Answers-The value where the model begins
What are linear equations are well-suited for... - Correct Answers-solving for a single variable in
terms of another that is clearly defined
Systems of Equations Definition - Correct Answers-Set of multiple equations with multiple
variables that are interdependent
Useful for modeling and simulaion
When the systems of equations gives an answer like 6=6 or 4=4, then the equations are... -
Correct Answers-Dependent, meaning the system has an infinite amount of solutions
When your system has no solution, it will graph as... - Correct Answers-Two parallel lines
When your system has one solution, it will graph as... - Correct Answers-Two lines that intersect
at a single point
When your system has infinite solutions, it will graph as... - Correct Answers-Two lines that
overlap, making one
Ways to solve Systems of Equations - Correct Answers-Substitution
Combination
Substitution Definition - Correct Answers-Solve the simpler of the two equations for one
, variable and then substitute the result into the other variable
r = 2x + 6
3r + 2x = 18
6x + 18 + 2x = 18
Combination Definition - Correct Answers-Adding the two equations together to eliminate a
variable
-5x + 7y = 39
5x + 9y = 1
16y = 40
Rates Formula - Correct Answers-Distance/work/result = rate * time`
Be sure to remember what units you're working in when doing this!
The conversions from feet to yards and square feet to square feet to square yards are... -
Correct Answers-Not the same!
Square feet * 1/3 * 1/3 = Square Yards
Ratios Definition - Correct Answers-Comparison of one quantity to another
Can compare a part to a part or a part to a whole
Combining Ratios - Correct Answers-To combine a:b and b:c, make b a common value to create
a:c
2:3 and 5:6, 10:15 and 15:18, 10:18
Proportion - Correct Answers-Two ratios set equal to each other
Check the units of each ratios and double-check your work by cross-multiplying
If a/b = c/d, then ad=bc, therefore b/a = d/a but not a/d=b/c
Percent Formula - Correct Answers-Percent = part/whole * 100%
Percent Change Formula - Correct Answers-Percent increase or decrease = (amount of increase
or decrease/original amount) * 100%
What's one thing that you need to be careful of when doing probabilities? - Correct Answers-
Don't just add two percentages together, provided you're not doing P(AuB) problems.
Anatomy of Exponents - Correct Answers-Made up of a base (the larger number) and an
exponent/power
