Question

Please help! Correct answer only, please! I need to finish this assignment this week. Determine the value of the following if it is possible. If it is not possible, explain. Matrix P has a dimensions of 3 X 4 and Matrix Q has the dimensions 4 X 5. Determine the dimensions of the matrix PQ if it is possible. Explain why if it is not. (refer to video part 4) Group of answer choices A. Matrix PQ would have the dimensions 3 X 4 B. Matrix PQ would have the dimensions 4 X 5 C. Matrix PQ would have the dimensions 3 X 5 D. These matrices can not be multiplied because their dimension don't align.

Answer 1

Answer: c) 3 x 5

Explanation:

When multiplying matrices of dimension m x n, the "inside" values MUST be the same. The dimension of their product is the "outside" values.

P = 3 x 4

Q = 4 x 5

The "inside" values are both 4 so the product can be found.

The "outside" values are 3 & 5 so the dimension of the product is 3 x 5.

If the problem was flipped to: find QP, we would get the following:

Q = 4 x 5

P = 3 x 4

the "inside" values of 3 & 5 are not the same so the product does not exist.