Question

Solve for x in the equation ? 2x^2 +3 x-7 =x^2 +5x +39

Answer 1

Answer:

1 ± √47

Step-by-step explanation:

Combine like terms in 2x^2 +3 x-7 =x^2 +5x +39:

2x^2 - x^2 = x^2 (first term);

3x - 5x = -2x (second term);

-7 - 39 = -46 (third term)

Then we have, all on the left side, x^2 - 2x - 46, which is a quadratic equation.  Here the coefficients are a = 1, b = -2 and c = -46.

Then the discriminant, b^2 - 4ac, is:

(-2)^2 - 4(1)(-46) = 4 + 184.

The roots are:

     -(-2) ±√188         2 ± √4√47

    ------------------- = -------------------

              2                         2

                             = 1 ± √47 (last of the answer choices)

=

x = ------------------