All PSAT Math Resources
Example Questions
Example Question #1201 : Psat Mathematics
Example Question #1202 : Psat Mathematics
Rationalize the denominator:
The conjugate of is .
Now multiply both the numerator and the denominator by
and you get:
Hence we get
Example Question #1203 : Psat Mathematics
Solve for :
Example Question #1204 : Psat Mathematics
Solve for .
Example Question #1205 : Psat Mathematics
If,
What does
If ,
then .
Example Question #16 : Exponents And Rational Numbers
From the equation in the problem statement
Now squaring both sides we get
this is a quadratic equation which equals
and the factors of this equation are
This gives us .
However, if we plug these solutions back into the original equation, does not create an equality. Therefore, is an extraneous solution.
Example Question #5 : How To Find A Rational Number From An Exponent
For some positive integer , if , what is the value of ?
If , then must equal 3 (Note that cannot be -3 because you need it to be positive.
Now, plug into the new equation :
Example Question #551 : Algebra
Factor 2x2 - 5x – 12
(x – 4) (2x – 3)
(x + 4) (2x + 3)
(x - 4) (2x + 3)
(x + 4) (2x + 3)
(x - 4) (2x + 3)
Via the FOIL method, we can attest that x(2x) + x(3) + –4(2x) + –4(3) = 2x2 – 5x – 12.
Example Question #111 : Exponents
x > 0.
Quantity A: (x+3)(x-5)(x)
Quantity B: (x-3)(x-1)(x+3)
Quantity A is greater
The two quantities are equal
The relationship cannot be determined from the information given
Quantity B is greater
Quantity B is greater
Use FOIL:
(x+3)(x-5)(x) = (x2 - 5x + 3x - 15)(x) = x3 - 5x2 + 3x2 - 15x = x3 - 2x2 - 15x for A.
(x-3)(x-1)(x+3) = (x-3)(x+3)(x-1) = (x2 + 3x - 3x - 9)(x-1) = (x2 - 9)(x-1)
(x2 - 9)(x-1) = x3 - x2 - 9x + 9 for B.
The difference between A and B:
(x3 - 2x2 - 15x) - (x3 - x2 - 9x + 9) = x3 - 2x2 - 15x - x3 + x2 + 9x - 9
= - x2 - 4x - 9. Since all of the terms are negative and x > 0:
A - B < 0.
Rearrange A - B < 0:
A < B
Example Question #1206 : Psat Mathematics
Solve for all real values of .
First, move all terms to one side of the equation to set them equal to zero.
All terms contain an , so we can factor it out of the equation.
Now, we can factor the quadratic in parenthesis. We need two numbers that add to and multiply to .
We now have three terms that multiply to equal zero. One of these terms must equal zero in order for the product to be zero.
Our answer will be .