What are the exact solutions of x2 − x − 4 = 0, where x equals negative b plus or minus the square root of b squared minus 4 times a times c all over 2 times a?

a: x = the quantity of negative 1 plus or minus the square root of 15 all over 2
b: x = the quantity of 1 plus or minus the square root of 15 all over 2
c: x = the quantity of 1 plus or minus the square root of 17 all over 2
d: x = the quantity of negative 1 plus or minus the square root of 17 all over 2

The answer is option C: x = the quantity of 1 plus or minus the square root of 17 all over 2

Step-by-step explanation:

The general form of the quadratic equation is ax² + bx + c = 0

The general solution of the quadratic equation is:

The given equation is x² − x − 4 = 0

So, a = 1 , b = -1 and b = -4

Substitute with a , b and c at the formula of the general solution.

The solution of the given equation =

Comparing the solution with the given options

So, the answer is option C: x = the quantity of 1 plus or minus the square root of 17 all over 2

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: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.