Answer:
7
Step-by-step explanation:
If there are 2 blue chairs and 5 red chairs there are 7 chairs total.
To multiply B and A, the number of columns of B must matc the number of rows of A.
<h3>
When we can multiply two matrices?</h3>
When we multiply two matrices, A and B, we multiply the rows of matrix A by the columns of matrix B.
Now, the number of elements in a row of a matrix, is equal to the number of columns (and the number of elements in a column is equal to the number of rows).
To multiply BxA:
Then, a row on matrix B must have the same number of elements than a column in row A.
Then, to multiply BxA, the number of columns of B must match the number of rows of A, meaning that the correct option is the last one.
If you want to learn more about matrices, you can read:
brainly.com/question/11989522
Answer:
s = 3x - (1/2)y
Step-by-step explanation:
The perimeter of a square is 4s, where s is the side length. Here,
12x - 2y = 4s, and so s = 3x - (1/2)y
