All ACT Math Resources
Example Questions
Example Question #101 : Variables
Which expression is equivalent to the following polynomial:
This question calls for us to factor the polynomial into two binomials. Since the first term is and the last term is a number without a variable, we know that how answer will be of the form where a and b are positive or negative numbers.
To find a and b we look at the second and third term. Since the second term is not present, we know . (The x comes from a and b multiplying by x and then adding with each other).
The term tells us that . Using these two pieces of information we can look at possible values. The third term tells us that -81 & 1, 81 & -1, and -9 & 9 are the possible pairs. Now we can look and see which one adds up to make 0.
This gives us the pair -9 & 9 and we plug that into the equation as a and b to get our final answer.
Example Question #101 : Variables
Factor the following polynomial:
To factor a polynomial of the form begin by factoring both and .
Since we are done.
When you factor your two factors need to add together to get .
Since:
and the two factors we want are and .
Simply plug them into the parentheses and you have:
Example Question #1 : How To Factor A Variable
Two consecutive positive multiples of five have a product of 300. What is their sum?
15
45
20
35
25
35
Define the variables as x = 1st number and x + 5 = 2nd number, so the product is given as x(x + 5) = 300, which becomes x2 + 5x – 300 = 0.
Factoring results in (x + 20)(x – 15) = 0, so the positive answer is 15, making the second number 20.
The sum of the two numbers is 35.
Example Question #1 : Factoring
Factor 12x3y4 + 156x2y3
12x2y3
x2y3(xy + 13)
12xy(xy + 13)
12x2y3(xy + 13)
12x2y3(xy + 13)
The common factors are 12, x2, and y3.
So 12x2y3(xy + 13)
Example Question #2 : Factoring
Solve for all solutions of :
First move all of the variables to the left side of the equation. Combine similar terms, and set the equation equal to zero. Then factor the equation to get
Thus the solutions of are 4 and 6.
Example Question #2 : How To Factor A Variable
Simplify:
factors to
One cancels from the bottom, leaving
Example Question #2 : How To Factor A Variable
Factor:
In the form of you must find two numbers which add to give you and multiply to give you and then put them in the form of ( + number) ( + number)
Therefore is the answer.
To check, multiply the two expressions out and it should equal
Example Question #3 : Factoring
Factor the following expression:
The expression is already simplified as much as possible.
To factor an expression we look for the greatest common factor.
Remember that
Thus:
Example Question #1 : Factoring
Factor the following expression:
To factor, you are looking for two factors of 40 that add to equal 13.
Factors of 40 include: (1, 40), (2, 20), (4, 10), (5, 8). Of these factors which two will add up to 13?
Also, since the first sign (-) and the second sign is (+) this tells us both binomials will be negative. This is because two negatives multiplied together will result in the positive third term, while two negatives added together will result in a larger negative number.
Thus,