Question

Solve this equation using the most direct method:

3x(x + 6) = -10

Enter your solution in the exact, most simplified form. If there are two solutions, write the answer using the ± symbol.

Answer 1

Answer:

√7

Step-by-step explanation:

3x(x + 6) = -10

=→ 3x^2+18x= -10

=→ 3x^2+ x = -10-18

=→ 4x^2 = -28

=→ x^2 = -28/4

=→ x = √7

Hope my answer helps you.

Answer 2

Given:

3x(x + 6) = -10

To Find:

Solve the equation

Solution:

We will first simplify the given equation 3x(x + 6) = -10

3x(x + 6) = -10

3x(x + 6) +10 = 0 (Taking 10 to the L.H.S)

3x²+18x + 10 = 0 (Multiplying by 3x)

Quadratic Formula

x = (-b±√D)/2a

Where,

b = coefficient of x

  =18

a = coefficient of x²

  =3

c = constant term

  =10

D is the Discriminant

D = (b²-4ac)

Let us first find D

D = (18²-(4×3×10))

  =324-120

 =204

Now,

x = (-b±√D)/2a

x = (-18±√204)/2×3

x = (-18±√2×2×3×17)/6   (Factorising 204)  

x = (-18±2√51)/6     (Taking 2 common)

x = (-9±√51)/3

Hence, the exact, most simplified form of solution is  (-9±√51)/3