All PSAT Math Resources
Example Questions
Example Question #71 : Algebra
varies inversely as both the square of and the square root of . Assuming that does not depend on any other variable, which statement is true of concerning its relationship to ?
varies directly as the fourth power of .
varies inversely as .
varies directly as the fourth root of .
varies inversely as the fourth power of .
varies inversely as the fourth root of .
varies inversely as the fourth power of .
varies inversely as both the square of and the square root of , meaning that for some constant of variation ,
.
Square both sides, and the expression becomes
takes the role of the new constant of variation here, and we now have
,
meaning that varies inversely as the fourth power of .
Example Question #72 : Algebra
varies directly as the square of and inversely as ; and . Assuming that does not depend on any other variables, which of the following gives the variation relationship of to ?
varies directly as .
varies directly as the fourth power of .
varies inversely as the seventh power of .
varies inversely as the fourth power of .
varies inversely as .
varies directly as .
varies directly as the square of and inversely as ; therefore, for some constant of variation ,
Setting and , the formula becomes
Setting as the new constant of variation, we have a new variation equation
,
meaning that varies directly as .
Example Question #71 : Algebra
If you have a rectangle with a width of and a length of , what is the area of the rectangle?
To find the area of a rectangle, multiply the length times the width. Therefore, you must multiply times . To do that, you must multiply the monomial times each part of the trinomial, like so:
Example Question #2 : How To Multiply A Monomial By A Polynomial
Find the product:
Use the distributive property:
Simplify: don't forget to use the rules of multiplying exponents (add them)
Example Question #3 : How To Multiply A Monomial By A Polynomial
Find the product:
Find the product:
Use the distributive property:
When multiplying variables with exponents, add the exponents:
Example Question #3 : Monomials
Find the product:
Find the product:
Use the distributive property:
Example Question #1 : Distributive Property
Example Question #1 : Distributive Property
If , what is the value of ?
Remember that (a – b )(a + b ) = a 2 – b 2.
We can therefore rewrite (3x – 4)(3x + 4) = 2 as (3x )2 – (4)2 = 2.
Simplify to find 9x2 – 16 = 2.
Adding 16 to each side gives us 9x2 = 18.
Example Question #3 : Distributive Property
If and , then which of the following is equivalent to ?
We are asked to find the difference between g(h(x)) and h(g(x)), where g(x) = 2x2 – 2 and h(x) = x + 4. Let's find expressions for both.
g(h(x)) = g(x + 4) = 2(x + 4)2 – 2
g(h(x)) = 2(x + 4)(x + 4) – 2
In order to find (x+4)(x+4) we can use the FOIL method.
(x + 4)(x + 4) = x2 + 4x + 4x + 16
g(h(x)) = 2(x2 + 4x + 4x + 16) – 2
g(h(x)) = 2(x2 + 8x + 16) – 2
Distribute and simplify.
g(h(x)) = 2x2 + 16x + 32 – 2
g(h(x)) = 2x2 + 16x + 30
Now, we need to find h(g(x)).
h(g(x)) = h(2x2 – 2) = 2x2 – 2 + 4
h(g(x)) = 2x2 + 2
Finally, we can find g(h(x)) – h(g(x)).
g(h(x)) – h(g(x)) = 2x2 + 16x + 30 – (2x2 + 2)
= 2x2 + 16x + 30 – 2x2 – 2
= 16x + 28
The answer is 16x + 28.
Example Question #2 : Distributive Property
The sum of two numbers is . The product of the same two numbers is . If the two numbers are each increased by one, the new product is . Find in terms of .
Let the two numbers be x and y.
x + y = s
xy = p
(x + 1)(y + 1) = q
Expand the last equation:
xy + x + y + 1 = q
Note that both of the first two equations can be substituted into this new equation:
p + s + 1 = q
Solve this equation for q – p by subtracting p from both sides:
s + 1 = q – p