Evaluate this expression when c= -2 and d= 2:

Step-by-step explanation:

you just have to put the given values in place of the variable names and then simply calculate.

(-2² + 2²) - 2(-2² - 2²) = (4 + 4) - 2(4 - 4) = 8 - 2×0 = 8

so, B is the right answer.

please remember the correct sequence of operations :

first are brackets.

then exponents.

then multiplications and divisions.

and then (at last) additions and subtractions.

and also please remember : multiplying a negative number with a negative number creates a positive result.

that is of course also true for squaring a negative number, as ² just means that the negative number is multiplied with itself.

now you also know the result of -2³, right ?

as this means -2 is multiplied 3 times by itself. what does that do to the sign ?

-2 × -2 = 4 (positive).

but now we have to multiply a third time

4 × -2 = -8 (because multiplying a positive number with a negative number creates a negative result).

5/12, or 5: 12

step-by-step explanation:

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