All PSAT Math Resources
Example Questions
Example Question #41 : Expressions
Which of the following numbers is eight more than half of itself?
10
4
24
8
16
16
Word problems like this are a common occurrence on the PSAT. Begin by setting the number we are looking for, let's call it , equivalent to the equation we are given in the words.
Move all terms with the variable to one side:
Multiply both sides by 2:
The correct answer is 16.
Example Question #41 : Expressions
Fahrenheit temperature can be converted to its Celsius equivalent using the formula
.
Celsius temperature can be converted to its Fahrenheit equivalent using the formula
.
Mercury boils at . To the nearest degree, convert this to its equivalent Fahrenheit temperature.
None of the other responses is correct.
The formula to use is
.
Substitute 357 for :
To the nearest degree, this is .
Example Question #1 : How To Simplify An Expression
Increase by 70%. Which of the following will this be equal to?
A number increased by 70% is equivalent to 100% of the number plus 70% of the number. This is taking 170% of the number, or, equivalently, multiplying it by 1.7.
Therefore, increased by 70% is 1.7 times this, or
Example Question #41 : Expressions
Which of the following phrases can be written as the algebraic expression ?
Nineteen less than the cube of a number
The cube of the difference of nineteen and a number
Three times the difference of a number and nineteen
The cube of the difference of a number and nineteen
Three times the difference of nineteen and a number
The cube of the difference of a number and nineteen
is the cube of , which is the difference of a number and nineteen; therefore, is "the cube of the difference of a number and nineteen."
Example Question #42 : Expressions
Which of the following phrases can be written as the algebraic expression ?
Seventeen decreased by the cube of a number
The cube of the difference of seventeen and a number
The cube of the difference of a number and seventeen
Three times the difference of seventeen and a number
Three times the difference of a number and seventeen
Seventeen decreased by the cube of a number
is seventeen decreased by , which is the cube of a number; therefore, is "seventeen decreased by the cube of a number."
Example Question #41 : Evaluating And Simplifying Expressions
Which of the following operations could represent the expression ?
2 times 7 less than the square of x
7 less than the square of 2x
7 more than 2 times the square of x
7 more than the square of 2x
2 times 7 more than the square of x
7 more than 2 times the square of x
Begin by putting the equation given into your own words. It might sound something similar to:
2 times x squared plus 7
Now, go through each answer choice and see if any of them are similar to this. We immediately see that the answer "7 more than 2 times the square of x" is similar to what we came up with. Let's do a quick run through of the other choices to be sure of our choice:
"2 times 7 more than the square of x" is equal to , which is equivalent to .
"2 times 7 less than the square of x" is equal to , which is equivalent to .
"7 more than the square of 2x" is equal to , which is equivalent to .
"7 less than the square of 2x" is equal to , which is equivalent to .
The only answer that works is "7 more than 2 times the square of x". This is the correct answer.
Example Question #3 : How To Simplify An Expression
What does equal?
When solving a complex expression, remember the acronym PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction). Reading left to right, begin by doing all operations within the innermost Parentheses first:
Continue simplifying using the acronym PEMDAS:
The expression is equal to -63.
Example Question #43 : Expressions
Simplify.
Same denominator means you add straight across the numerators, keeping the denominator the same.
Add like terms.
Final Answer.
Example Question #44 : Expressions
Simplify.
Check for same Denominator
Add like terms
Check for GCF or if the expression can be factored
After factoring, divide out like terms.
Final Answer
Example Question #1 : How To Add Rational Expressions With A Common Denominator
Simplify the following rational expression: (9x - 2)/(x2) MINUS (6x - 8)/(x2)
Since both expressions have a common denominator, x2, we can just recopy the denominator and focus on the numerators. We get (9x - 2) - (6x - 8). We must distribute the negative sign over the 6x - 8 expression which gives us 9x - 2 - 6x + 8 ( -2 minus a -8 gives a +6 since a negative and negative make a positive). The numerator is therefore 3x + 6.
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