Determine the numbers b, c that the numbers x1 = -1 and x2 = 3 were roots of quadratic equation:

$-3x 2 + b x + c = 0$

Result

b =  6
c =  9

#### Solution:

$a = -3 \ \\ b = -a x_1 - a x_2 = 6$
$c = a x_1 x_2 = 9 \ \\ -3x ^2 +6x +9 = 0$

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