Flashcard 4 - Mathematics Flashcard Set for the HiSET Test

\[x = \frac{{6 \pm \sqrt {{{( - 6)}^2} - 4(5)(8)} }}{{2(5)}}\]

The quadratic formula is used to solve the quadratic equation: \(a{x^2} + bx + c = 0\)

The formula is: \(x = \frac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}\)

In the given equation, \(5{x^2} - 6x + 8 = 0;\;a = 5,\;b = - 6,\;{\rm{and}}\;c = 8.\)

Therefore, \(x = \frac{{6 \pm \sqrt {{{( - 6)}^2} - 4(5)(8)} }}{{2(5)}}\)

Note: The quadratic equation is one of the three formulas you’ll need to memorize before taking this test because it is not given on the formula sheet. The others are the Pythagorean theorem and the distance formula.