ACT Math : How to subtract matrices

Study concepts, example questions & explanations for ACT Math

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Example Questions

Example Question #1 : Find The Sum Or Difference Of Two Matrices

Given the following matrices, what is the product of  and ?

 

Possible Answers:

Correct answer:

Explanation:

When subtracting matrices, you want to subtract each corresponding cell.

 

 

Now solve for  and 

 

 

Example Question #1 : Matrices

If , what is ?

 

Possible Answers:

Correct answer:

Explanation:

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

 

Possible Answers:

 

 

Correct answer:

 

Explanation:

When subtracting matrices, subtracting component-wise.

Example Question #1 : How To Subtract Matrices

If , then what is the value of  ?

Possible Answers:

0

15

3

26

12

Correct answer:

15

Explanation:

 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 (lower right).

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