What are all of the real roots of the following polynomial? f(x) = x^4 -24x^2 - 25 a. -1 or 1 b. -5 or 5 c. -5, -1, 1, or 5 d. -5 or -1 ?

For this case we have the following function:

We make a change of variable:

So, we have:

We apply the resolver:

We have two roots:

Returning the change:

Give the imaginary roots.

Real roots

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.