What should the value of b in x^2 + bx - 55 = 0 so that its solutions are -11 and 5?

A. -16
B. 16
C. -6
D. 6

1 answer

To find the value of b, we can use the fact that the sum of the solutions of a quadratic equation in the form ax^2 + bx + c = 0 is equal to -b/a.

In this case, the sum of the solutions is (-11) + 5 = -6.

We can set up the equation -6 = -b/a and solve for b:
-6 = -b/a
Multiply both sides of the equation by a:
-6a = -b
Divide both sides of the equation by -1:
6a = b

Therefore, the value of b is 6.

The correct answer is D. 6.