Apolynomial expression is shown below.

(mx+8)(2x−4)

the expression is simplified to:

−6x2+28x−32

what is the value of m?

a) -3

b) 4

c) 3

d) -4

m = -3

Step-by-step explanation:

The polynomial expression

(mx+8)(2x−4)

The next step is to expand the bracket

(mx × 2x) + (mx × -4) + (8×2x) + (8× -4)

2mx^2 - 4mx + 16x -32

2mx^2 - 4mx + 16x -32

2mx^2 + 12x -32 - - - - - - - - - - 1

From the question,

The expression is simplified to

−6x2+28x−32 - - - - - - - - - - - - 2

This means equation 1 = equation 2

Comparing both equations, we have

2mx^2 = −6x^2

2m = -6

m = -6/2 = -3

The correct option is a

The expression becomes

(-3x+8)(2x−4)

Let us check

Expanding the brackets,

(-3x × 2x) + (-3x ×-4)+ (8×2x) + (8×-4)

= -6x^2 +12x + 16x - 32

= -6x^2 +18x - 32

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m

answer: what are the following choices