How do you solve (3x+3)(x+2)=2?

2 Answers
Jul 10, 2015

x = (-9 + sqrt(33)) / 6 or (-9 - sqrt(33)) / 6

Explanation:

Simplify the right-hand-side by expanding,

(3x+3)(x+2) = 3x^2 + 9x + 6

Bring the 2 to the left hand side [Think of subtracting both sides by 2]. Then the equation becomes:

3x^2 + 9x + 4 = 0

Solve this using the quadratic formula:

x = (-9 +- sqrt(81 - 4*12))/6 = (-9 +- sqrt(33)) / 6

Thus, x = { (-9 + sqrt(33)) / 6, (-9 - sqrt(33)) / 6 }

Jul 10, 2015

x=(-9+sqrt(33))/6,(-9-sqrt(33))/6

Explanation:

(3x+3)(x+2)=2

FOIL the left side of the equation.

3x^2+6x+3x+6=2 =

3x^2+9x+6=2

Subtract 2 from both sides.

3x^2+9x+6-2=0 =

3x^2+9x+4=0

The equation is now in the form of a quadratic equation: ax^2+bx+c=0, where a=3; b=9; and c=4.

Use the quadratic formula to solve this equation.

Quadratic Formula

x=(-b+-sqrt(b^2-4ac))/(2a) =

x=(-9+-sqrt(9^2-4*3*4))/(2*3) =

x=(-9+-sqrt(81-48))/6 =

x=(-9+-sqrt(33))/6

Two answers for x.

x=(-9+sqrt(33))/6

x=(-9-sqrt(33))/6