Question

When the solution of x2 − 9x − 6 is expressed as 9 plus or minus the square root of r, all over 2, what is the value of r? X equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a 6 42 57 105

Answer 1

105 is right

Explanation:

I took the test

Answer 2

The value of r is 105

Explanation:

Quadratic equation helps us to solve any quadratic equation. The formula is:

(-b ± √b² - 4ac) ÷ 2a

For the quadratic equation ax²+bx+c

For the equation: X² - 9x - 6:

a = 1, b = -9 and c = -6

Replacing in the quadratic formula:

(-(-9) ± √(-9)² - 4(1*-6)) ÷ 2*1

= 9 ± √105 / 2

That means, the value of r is 105