Solve Using the Quadratic Formula 9x^2+21x-8=0

Problem

9*x2+21*x−8=0

Solution

1. Identify the coefficients a b and c from the quadratic equation in the form a*x2+b*x+c=0

a=9

b=21

c=−8

2. Apply the quadratic formula which is given by x=(−b±√(,b2−4*a*c))/(2*a)

x=(−21±√(,21−4*(9)*(−8)))/(2*(9))

3. Simplify the expression inside the square root (the discriminant).

x=(−21±√(,441+288))/18

x=(−21±√(,729))/18

4. Calculate the square root of 729

√(,729)=27

x=(−21±27)/18

5. Solve for the two possible values of x by evaluating the plus and minus cases.

(x_1)=(−21+27)/18=6/18=1/3

(x_2)=(−21−27)/18=(−48)/18=−8/3

Final Answer

x=1/3,−8/3

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