Question

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

Answer 1

Answer:C: x = the quantity of 1 plus or minus the square root of 17 all over 2

Explanation:

Answer 2

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

Explanation:

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

The general solution of the quadratic equation is:

`x=(-b \pm √(b^2-4ac) )/(2a)`

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 =
`(-(-1) \pm √((-1)^2 - 4 * 1 * (-4)) )/(2*1)= (1\pm √(1 +16) )/(2)=(1\pm √(17) )/(2)`

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