Simplify: (5x2 - 3x - 4)(3x - 7) A. 15x3 - 44x2 + 9x - 28 B. 15x3 - 44x2 + 9x + 28 C. 15x3 + 26x2 - 33x - 28 D. 15x3 - 26x2 - 33x + 28

A. 15x^3 -44x^2 +9x +28

Step-by-step explanation:

(5x^2 -3x -4)(3x - 7)

first, distribute by multiplying the terms in each parenthesis with each other:

(5x^2 * 3x) - (3x * 3x) - (4 * 3x) - (5x^2 * 7) + (3x * 7) + (4 * 7)

simplify:

15x^3 -35x^2 -9x^2 +21x -12x +28

Now combine like terms:

15x^3 -44x^2 +9x +28

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.