All PSAT Math Resources
Example Questions
Example Question #25 : Algebraic Functions
Quantity A Quantity B
The relationship cannot be determined from the information given.
Quantity A and Quantity B are equal
Quantity B is greater
Quantity A is greater
Quantity A and Quantity B are equal
Since , then we have that
and
.
Thus, the two quantities are equal.
Example Question #81 : Algebraic Functions
If the average of two numbers is and one of the numbers is , what is the other number, in terms of and ?
The average is the sum of the terms divided by the number of terms. Here you have and the other number which you can call . The average of and is . So
Multiply both sides by 2.
Solve for .
Example Question #23 : Algebraic Functions
Alice is twice as old as Tom, but four years ago, she was three years older than Tom is now. How old is Tom now?
The qustion can be broken into two equations with two unknows, Alice age and Tom's age .
Example Question #82 : Algebraic Functions
A jet goes from City 1 to City 2 at an average speed of 600 miles per hour, and returns along the same path at an average speed if 300 miles per hour. What is the average speed, in miles per hour, for the trip?
300miles/hour
400miles/hour
450miles/hour
500miles/hour
350miles/hour
400miles/hour
Chose a number for the distance between City 1 and 2; 1800 works well, as it is a multiple of 600 and 300.
Now, find the time for each trip, the total distance, and the total time.
Now we can find the average speed by dividing the total distance by the total time.
Example Question #29 : Algebraic Functions
Find .
Plug 5 into first:
Now, plug this answer into :
Example Question #83 : Algebraic Functions
If and , what is ?
Plug g(x) into f(x) as if it is just a variable. This gives f(g(x)) = 3(x2 – 12) + 7.
Distribute the 3: 3x2 – 36 + 7 = 3x2 – 29
Example Question #84 : Algebraic Functions
f(x) = 4x + 17
Solve f(x) for the equation above for x = 3.
12
29
32
19
26
29
The correct answer is 29. We plug in 3 into the equation above and solve for x. So we find that f(x) = 4(3) + 17. 12 + 17 = 29
Example Question #1211 : Algebra
For which value of are the following two functions equal?
6
3
5
2
4
4
It is important to follow the order of operations for this equation and find a solution that satisfies both F(x) and G(x).
Recall the order of operations is PEMDAS: Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.
The correct answer is 4 because
F(x) = 2x + 3x + (9x/3) = 2(4) + 34 + ((9 * 4)/3) = 101, and
G(x) = (((24 + 44)/2) - 4 * 4) – 5(4) + 1 = 101.
Example Question #201 : Algebraic Functions
The function is defined as . What is ?
24
56
-36
36
18
24
Substitute -1 for in the given function.
If you didn’t remember the negative sign, you will have calculated 36. If you remembered the negative sign at the very last step, you will have calculated -36; however, if you did not remember that is 1, then you will have calculated 18.
Example Question #2912 : Sat Mathematics
If the function is created by shifting up four units and then reflecting it across the x-axis, which of the following represents in terms of ?
We can take each of the listed transformations of one at a time. If is to be shifted up by four units, increase every value of by 4.
Next, take this equation and reflect it across the x-axis. If we reflect a function across the x-axis, then all of its values will be multiplied by negative one. So, can be written in the following way:
Lastly, distribute the negative sign to arrive at the final answer.
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