What is the product of ( 7 − 3 i ) × ( 4 + i ) ?

31-5i

Step-by-step explanation:

28+7i-12i-3i^2

28-5i+3

31-5i

31 - 5i

Step-by-step explanation:

(7 - 3i) * (4 + i)

Step 1: Multiply complex numbers 7 − 3i and 4 + i like you multiply binomials.

7 * 4 + 7i - 3i * 4 - 3i²

Step 2: By definition, i² is -1.

7 * 4 + 7i - 3i * 4 - 3 ( - 1)

Step 3: Do the multiplications.

28 + 7i - 12i + 3

Step 4: Combine the real & imaginary parts.

28 + 3 + (7 - 12)i

Step 5: Do the additions.

31 - 5i

The product of (7 - 3i) and 4 + i is 31 - 5i.

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.