algebra 2 help?

Question

Use the quadratic formula to solve each equation.

9x^2 + 12x + 5 = 0

Answer 1

Hi,
............___________
-12 ± √12^2 - 4*9*5
----------------------------- Fill in the formula a = 9, b = 12, c = 5
............2*9

............_________
-12 ± √144 - 180
------------------------- simplify the expression
............18

............____
-12 ± √ - 36
------------------ square root of -36 gives the imaginary "6i"
.......18

-12 ± 6i
------------------ reduce by dividing everything by 6
......18

-2 ± i
---------
......3


I hope that helps!! :-)

Answer 2

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

a=9
b=12
c=5

Discriminant is (b^2 - 4*a*c)

So that will be 12*12 - 4*9*5 = 144-180 = -36
sqrt(-36) = 6i where i is sqrt(-1). This is an imaginary number

So the final answer would be
(-12+6i)/(2*9) = -2/3 + 1/3 i
(-12+6i)/(2*9) = -2/3 - 1/3 i

In fact from theory of quadratic equations, once you find one of the roots (if it is imaginary), then the other is simple the complex conjugate of it. (i.e just change the sign of the imaginary part and you have the second root)

Answer 3

9x² + 12x + 5 = 0

general quadratic formula and solution
ax² + bx + c = 0
x = (-b +- √(b² - 4ac))/2a

your problem
x = (-12 +- √(144 - 180))/18

x = (-12 +- √(-36))/18

x = (-12 +- 6i)/18, i = √(-1)

Divide thru by 6

x = (-2 + i)/3, x = (-2 - i)/3
.

Answer 4

Use the formula in yoru book labeled Quadratic Equation. Your variables are:

a=9
b=12
c=5

Answer 5

x = -b +- sqrt. (b2 - 4ac) / 2a is the quadratic formula

a = 9, b = 12 and c = 5

x = -12 + sqrt (144 - 180) / 18

Since the value under the sqrt. is negative, the roots of the equation are imaginary.