Evaluate the products. a)√9.√4b)√9.√-4c)√-9.√4d)√-9.√-4

a) 6

b) 6i

c) 6i

d) -6

Step-by-step explanation:

We are going to write down the numbers as a product of prime numbers and then proceed to solve:

Note: Remember that i = √-1 and that i²= -1

a) √9(√4)

√3² × √2² = 3 × 2 = 6

Thus, the answer is 6

b) √9 ×√-4

√3² x i√2² = 3 x 2i = 6i

Thus, the answer is 6i

c) √-9.√4

i√3² × √2² = 3i x 2 = 6i

Thus the answer is 6i

d) √-9.√-4

i√3² × i√2²

3i x 2i = -6

Thus the answer is -6

c

step-by-step explanation:

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.