Respuesta :

Answer:

x = 1.47  or x = -7.47

Step-by-step explanation:

x²+6x+9=20

This is a quadratic equation

x²+6x+9-20=0

x²+6x-11=0

Step 1 : Write the quadratic formula

x = -b±√b²-4(a)(c)

              2a

Step 2 : Substitute values in the formula

a = 1

b = 6

c = -11

x = -6±√6²-4(1)(-11)

              2(1)

x = -6±√80

          2

x = -3 + 2√5 or x = -3 - 2√5

x = 1.47         or x = -7.47

!!

Answer:

x=1.472 or x=-7.472

Step-by-step explanation:

Lets begin by rearranging the equation into the format ax²+bx+c=0

The equation will be:

x²+6x+9-20=0

x²+6x-11=0

We shall use the quadratic formula to solve the equation.

x=[-b±√(b²-4ac)]/2a

=[-6±√(6²-4×1×-11)]/2

=[-6±√80]/2

=[-6±8.944]2

x= Either (-6+8.944)/2 or x= (-6-8.944)/2

Solving for x in each case gives:

x=1.472 or x=-7.472