Question

Solve the equation with the quadratic formula 4k^2-11k-18=0

Answer 1

Answer:

D

Step-by-step explanation:

Quadratic formula tells us that the roots are equal to:

$\frac{-b\pm \:\sqrt{b^2-4ac}}{2a}$

The letters are just the coefficients, so a = 4, b = -11, and c = -18. Plugging these values into the formula we get:

$\frac{-11\pm \sqrt{11^2-4\cdot \:4\left(-18\right)}}{2\cdot \:4}$

Which when simplified tells us that the roots are:

$\frac{-11+\sqrt{409}}{8}$ or $\frac{-11-\sqrt{409}}{8}$

Remember the plus or minus sign is what gives us two answers.