Solve Using the Quadratic Formula x^2+9x+20=0

Problem

x2+9*x+20=0

Solution

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

a=1

b=9

c=20

2. State the quadratic formula used to find the roots of the equation.

x=(−b±√(,b2−4*a*c))/(2*a)

3. Substitute the identified values into the quadratic formula.

x=(−9±√(,9−4*(1)*(20)))/(2*(1))

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

x=(−9±√(,81−80))/2

x=(−9±√(,1))/2

5. Evaluate the square root and solve for the two possible values of x

x=(−9±1)/2

6. Calculate the first solution using the plus sign.

x=(−9+1)/2=(−8)/2=−4

7. Calculate the second solution using the minus sign.

x=(−9−1)/2=(−10)/2=−5

Final Answer

x=−4,−5

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