Question

X² - 7x = 9

Answer 1

Answer:

x=7+ the square root of 85 /2  ,  x = 7- the square root of 85/2

Step-by-step explanation: hope I helped

Answer 2

Answer:

$x = \frac{7 + \sqrt{85} }{2} \:\: or \:\: \frac{7 - \sqrt{85} }{2}$

Step-by-step explanation:

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FACTS TO KNOW BEFORE SOLVING :-

Quadratic Formula :-

For a quadratic equation ax² + bx + c = 0 , by using quadratic formula the roots of the equation are :-

$x = \frac{-b + {\sqrt{b^2 - 4ac} } }{2a} \:\: or \:\: \frac{-b - \sqrt{b^2 - 4ac} }{2a}$

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Lets solve the equation x² - 7x - 9 = 0 by quadratic formula.

$=> x = \frac{-(-7) + \sqrt{(-7)^2 - 4 \times 1 \times (-9)} }{2 \times 1} \:\: or \:\: \frac{-(-7) - \sqrt{(-7)^2 - 4 \times 1 \times (-9)} }{2 \times 1}$

$=> x = \frac{7 + \sqrt{85} }{2} \:\: or \:\: \frac{7 - \sqrt{85} }{2}$