All PSAT Math Resources
Example Questions
Example Question #1 : Binomials
Decrease by 40%. Which of the following will this be equal to?
A number decreased by 40% is equivalent to 100% of the number minus 40% of the number. This is taking 60% of the number, or, equivalently, multiplying it by 0.6.
Therefore, decreased by 40% is 0.6 times this, or
Example Question #1 : Binomials
Find the product:
Find the product:
Use the distributive property:
Write the resulting expression in standard form:
Example Question #2162 : Sat Mathematics
If 〖(x+y)〗2 = 144 and 〖(x-y)〗2 = 64, what is the value of xy?
20
16
18
22
20
We first expand each binomial to get x2 + 2xy + y2 = 144 and x2 - 2xy + y2 = 64. We then subtract the second equation from the first to find 4xy = 80. Finally, we divide each side by 4 to find xy = 20.
Example Question #1 : Binomials
Which of these expressions can be simplified further by collecting like terms?
None of the expressions in the other choices can be simplified further
None of the expressions in the other choices can be simplified further
A binomial can be simplified further if and only if the two terms have the same combination of variables and the same exponents for each like variable. This is not the case in any of the four binomials given, so none of the expressions can be simplified further.
Example Question #2161 : Sat Mathematics
Solve for .
Factor the expression
numerator: find two numbers that add to 2 and multiply to -8 [use 4,-2]
denominator: find two numbers that add to 5 and multiply to -14 [use 7,-2]
new expression:
Cancel the and cross multiply.
Example Question #2 : How To Find The Value Of The Coefficient
Give the coefficient of in the product
While this problem can be answered by multiplying the three binomials, it is not necessary. There are three ways to multiply one term from each binomial such that two terms and one constant are multiplied; find the three products and add them, as follows:
Add:
The correct response is .
Example Question #1 : How To Find The Value Of The Coefficient
Give the coefficient of in the binomial expansion of .
If the expression is expanded, then by the binomial theorem, the term is
or, equivalently, the coefficient of is
Therefore, the coefficient can be determined by setting
:
Example Question #1 : How To Find The Value Of The Coefficient
Give the coefficient of in the binomial expansion of .
If the expression is expanded, then by the binomial theorem, the term is
or, equivalently, the coefficient of is
Therefore, the coefficient can be determined by setting
:
Example Question #3 : How To Find The Value Of The Coefficient
Give the coefficient of in the binomial expansion of .
If the expression is expanded, then by the binomial theorem, the term is
or, equivalently, the coefficient of is
Therefore, the coefficient can be determined by setting
Example Question #2 : How To Find The Value Of The Coefficient
Give the coefficient of in the product
.
While this problem can be answered by multiplying the three binomials, it is not necessary. There are three ways to multiply one term from each binomial such that two terms and one constant are multiplied; find the three products and add them, as follows:
Add:
The correct response is -122.