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Example Questions
Example Question #1 : Find The Sum Or Difference Of Two Matrices
If , what is
?
You can treat matrices just like you treat other members of an equation. Therefore, you can subtract the matrix
from both sides of the equation. This gives you:
Now, matrix subtraction is simple. You merely subtract each element, matching the correlative spaces with each other:
Then, you simplify:
Therefore,
Example Question #2581 : Act Math
When subtracting matrices, subtracting component-wise.
Example Question #2581 : Act Math
If , then what is the value of
?
15
0
3
12
26
15
Match each term from the first matrix with the corresponding number from the second matrix and subtract.
Simplify.
Each of the numbers in the matrix solution now corresponds to the letters, a through f. Add a (upper left) and f (lower right).
Example Question #1 : How To Find Combinations With A Matrix
Matthew, Emily, Cynthia, John, and Stephanie are all running for student council. If three equivalent positions are available in this year's election, how many different leadership boards are possible?
One possible approach is to enumerate all possibilities using initials for names (ie. MEC, MEJ, MES, etc). If we recognize that order does not matter in this problem, we can also enter into our calculators, and that will give us the answer of
.
Example Question #31 : Matrices
Simplify.
When we are asked to simplify a matrix that is being multiplied by a constant we simply multiply each component of the matrix with the scalar factor that is on the outside of the matrix.
Therefore,
Example Question #32 : Matrices
At a sale, a necklace that was originally is marked ten percent off. Cara has a coupon that will allow her to get ten percent off the discounted price. How much will Cara pay for the necklace if she uses the coupon?
Taking ten percent off of gives us
,
.
Taking ten percent off of this amount gives us
.
NOTE: This problem cannot be solved by taking twenty percent off of .
Example Question #1 : Foil
For all x, (4x – 3)2 =
12x2 + 24x – 9
16x2 – 9
16x2 + 24x + 9
16x2 + 9
16x2 – 24x + 9
16x2 – 24x + 9
To solve this problem, you should FOIL: (4x – 3)(4x – 3) = 16x2 – 12x – 12x + 9 = 16x2 – 24x + 9.
Example Question #1 : Distributive Property
Which of the following is equivalent to (2g – 3h)2?
4g2 – 6gh + 9h2
4g2 – 12gh + 9h2
4g2 – 12gh + 3h2
4g2 + 9h2
g2 – 12gh + 9h2
4g2 – 12gh + 9h2
Use FOIL: (2g – 3h)(2g – 3h) = 4g2 – 6gh – 6gh + 9h2 = 4g2 – 12gh + 9h2
Example Question #2 : How To Use Foil With The Distributive Property
Use FOIL on the following expression:
x(x + 1)(x – 1)
x2 – x
x
x – 1
x3 – x2
x3 – x
x3 – x
FOIL (First, Outside, Inside, Last): (x + 1)(x – 1) which is (x2 – 1) then multiply it by x, which is (x3 – x)
Example Question #3 : Distributive Property
Multiply: (4x + 3)(2x + 4)
30x + 12
3x² + 12x – 12
8x² + 22x +12
6x² + 16x + 24
8x² + 34
8x² + 22x +12
To solve you must use FOIL (first outer inner last)
Multiply 4x and 2x to get 8x²
Multiply 4x and 4 to get 16x
Multiply 3 and 2x to get 6x
Multiply 3 and 4 to get 12
Add the common terms and the awnser is 8x² + 22x + 12
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