All ISEE Upper Level Quantitative Resources
Example Questions
Example Question #911 : Isee Upper Level (Grades 9 12) Quantitative Reasoning
is a real number such that . Which is the greater quantity?
(a)
(b) 11
(b) is the greater quantity
(a) and (b) are equal
(a) is the greater quantity
It is impossible to determine which is greater from the information given
It is impossible to determine which is greater from the information given
By the Power of a Power Principle,
Therefore, is a square root of 121, of which there are two - 11 and . Since it is possible for a third (odd-numbered) power of a real number to be positive or negative, we cannot eliminate either possibility, so either
or
.
Therefore, we cannot determine whether is less than 11 or equal to 11.
Example Question #912 : Isee Upper Level (Grades 9 12) Quantitative Reasoning
By the Power of a Product Principle,
Also, by the Power of a Power Principle
Therefore,
Example Question #11 : How To Find The Exponent Of Variables
is a negative number. Which is the greater quantity?
(a)
(b)
(a) is the greater quantity
(b) is the greater quantity
(a) and (b) are equal
It is impossible to determine which is greater from the information given
(b) is the greater quantity
Any nonzero number raised to an even power, such as 4, is a positive number. Therefore,
is the product of a negative number and a positive number, and is therefore negative.
By the same reasoning, is a positive number.
It follows that .
Example Question #914 : Isee Upper Level (Grades 9 12) Quantitative Reasoning
Evaluate .
By the Power of a Power Principle,
By way of the Power of a Quotient Principle,
.
Example Question #915 : Isee Upper Level (Grades 9 12) Quantitative Reasoning
and are both real numbers.
Evaluate .
, as the product of a sum and a difference, can be rewritten using the difference of squares pattern:
By the Power of a Power Principle,
Therefore, is a square root of - that is, a square root of 121. 121 has two square roots, and 121, but since is real, must be the positive choice, 11. Similarly, is the positive square root of 81, which is 9.
The above expression can be evaluated as
.
Example Question #21 : Variables And Exponents
Which is the greater quantity?
(a)
(b) 37
(a) and (b) are equal
It is impossible to determine which is greater from the information given
(b) is the greater quantity
(a) is the greater quantity
It is impossible to determine which is greater from the information given
Multiply the polynomials through distribution:
The absolute value of is 4, so either or . Likewise, or .
If and , we see that
If and , we see that
In the first scenario, ; in the second, . This makes the information insufficient.
Example Question #22 : Variables And Exponents
Which is the greater quantity?
(a)
(b)
(b) is the greater quantity
(a) is the greater quantity
(a) and (b) are equal
It is impossible to determine which is greater from the information given
(a) is the greater quantity
The absolute value of is 4, so either or . Likewise, or . However, since and , it follows that regardless, and .
As the product of the sum and the difference of the same two expressions, can be rewritten as the difference of the squares of the expressions:
Using the Power of a Product Principle:
Substituting,
Similarly,
Therefore, .
Example Question #23 : Variables And Exponents
Which is the greater quantity?
(a)
(b) 16
(a) and (b) are equal
(a) is the greater quantity
(b) is the greater quantity
It is impossible to determine which is greater from the information given
(b) is the greater quantity
Multiply the polynomials through distribution:
Collecting like terms, the above becomes
By the Power of a Power Principle,
This makes a square root (positive or negative) of , or 81, so
or
We can not eliminate either since an odd power of a number can have any sign, and we are not given the sign of .
By similar reasoning, either
or
can assume one of four values, depending on which values of and are selected:
Regardless of the choice of and , .
Example Question #24 : Variables And Exponents
Define .
is a function with the set of all real numbers as its domain.
Which is the greater quantity?
(a)
(b)
(b) is the greater quantity
(a) is the greater quantity
(a) and (b) are equal
It is impossible to determine which is greater from the information given
It is impossible to determine which is greater from the information given
, so .
By definition,
.
Since and , we can determine that
.
However, this does not tell us the value of at . Therefore, we do not know whether or , if either, is the greater.
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