All SAT Math Resources
Example Questions
Example Question #1 :How To Multiply A Monomial By A Polynomial
Multiply:
Distribute the monomial through the polynomial.
The answer is:
Example Question #1 :Variables
Evaluate:
Distribute the monomial through each term inside the parentheses.
Example Question #1 :Variables
Multiply the monomials:
In order to multiply this, we can simply multiply the coefficients together and the变量联系在一起。当我们把一个变量of the same base, we can add the exponents.
Simplify the right side.
The answer is:
Example Question #1 :Variables
Distribute:
Distribute the monomial to each part of the polynomial, paying careful attention to signs:
Example Question #1 :How To Multiply Monomial Quotients
Find the product:
Find the product:
Step 1: Multiply the numerators and denominators using the properties of exponents. (When multiplying exponents, add them.)
Step 2: Simplify the expression.
Example Question #1 :Variables
Phillip can paintsquare feet of wall per minute. What area of the wall can he paint in 2.5 hours?
Every minute Phillip completes anothersquare feet of painting. To solve for the total area that he completes, we need to find the number of minutes that he works.
There are 60 minutes in an hour, and he paints for 2.5 hours. Multiply to find the total number of minutes.
如果he completessquare feet per minute, then we can multiplyby the total minutes to find the final answer.
Example Question #1 :How To Use The Direct Variation Formula
The value ofvaries directly with the square ofand the cube of. Ifwhenand, then what is the value ofwhenand?
Let's consider the general case whenyvaries directly withx. Ifyvaries directly withx, then we can express their relationship to one another using the following formula:
y=kx, wherekis a constant.
Therefore, ify成正比的平方xand the cube ofz, we can write the following analagous equation:
y=kx2z3, wherekis a constant.
The problem states thaty= 24 whenx= 1 andz= 2. We can use this information to solve forkby substituting the known values fory,x, andz.
24 =k(1)2(2)3=k(1)(8) = 8k
24 = 8k
Divide both sides by 8.
3 =k
k= 3
Now that we havek, we can findyif we knowxandz. The problem asks us to findywhenx= 3 andz= 1. We will use our formula for direct variation again, this time substitute values fork,x, andz.
y=kx2z3
y= 3(3)2(1)3= 3(9)(1) = 27
y= 27
The answer is 27.
Example Question #1 :How To Use The Direct Variation Formula
In a growth period, a population of flies triples every week. If the original population had 3 flies, how big is the population after 4 weeks?
We know that the initial population is 3, and that every week the population will triple.
The equation to model this growth will be, whereis the initial size,is the rate of growth, andis the time.
In this case, the equation will be.
Alternatively, you can evaluate for each consecutive week.
Week 1:
Week 2:
Week 3:
Week 4:
Example Question #4 :Direct And Inverse Variation
andare the diameter and circumference, respectively, of the same circle.
Which of the following is a true statement? (Assume all quantities are positive)
varies directly as the fourth root of.
varies directly as the fourth power of.
varies inversely as the fourth root of.
varies inversely as the fourth power of.
varies directly as.
varies directly as.
如果andare the diameter and circumference, respectively, of the same circle, then
.
By substitution,
Taking the square root of both sides:
Taking作为the constant of variation, we get
,
meaning thatvaries directly as.
Example Question #1 :Direct And Inverse Variation
is the radius of the base of a cone;is its height;is its volume.
;.
Which of the following is a true statement?
varies directly as the fifth power of.
varies directly as the fifth root of.
varies directly as.
varies directly as the cube root of.
varies directly as the third power of.
varies directly as the fifth power of.
The volume of a cone can be calculated from the radius of its base, and the height, using the formula
, so.
, so.
, so by substitution,
Square both sides:
如果we take作为the constant of variation, then
,
andvaries directly as the fifth power of.