Question

In the quadratic formula, what are a, b, and c for the following problem? - x ^ 2 + 2x = - 6

Answer 1

$\tt - x ^{2} + 2x = - 6$

Rewrite the equation in standard form i.e. ax²+bx+c=0

$\tt \: x ^{2} - 2x - 6 = 0$

Solve the quadratic equation using the quadratic formula, Put the values into the formula and then compare the values a,b & c

$\boxed{ \sf \: quadratic \: formula: x = \frac{ - b± \sqrt{b ^{2} - 4ac} }{2a} }$

Plug in the values and compare

$\tt \: x = \frac{ - ( - 2)± \sqrt{( - 2) ^{2} - 4 \times 1 \times ( - 6) } }{2 \times 1}$

On comparing we get,

• a = 1
• b = -2
• c = -6