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Solve 9x^2 + 12x - 24 = 0​

User Nizzam
by
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1 Answer

6 votes

Answer:

x = (-2 + √3)/3 and (-2 - √3)/3

Explanation:

Use quadratic equation to solve.

The standard form of a quadratic equation is

y = ax² + bx + c

For our equation, we have a = 9, b = 12, and c = -24

Quadratic equation is...

x = -b/(2a) ± [√(b² - 4ac)/(2a)]

Plug in our values and simplify...

x = -12/(2*9) ± [√(12² - 4(9)(-24))/(2*9)]

x = -12/18 ± [√(144 + 864)/18]

x = -2/3 ± (√1008)/18

√1008 = 12√7 (use a factor tree)

So x = -2/3 ± (12√7)/18

x = -2/3 ± (√7)/3

x = (-2 ± √7)/3

x = (-2 + √3)/3 and (-2 - √3)/3

User Mike Kovetsky
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5.3k points