SOLUTION: I need some help with this problem please : 5x^2 + 12x = -9 A x = (-6 +- 3i)/5 B x = (6 +- -3i)/5 C x = (3 +- 6i)/12 D x = (3 +- 6i)/5 E x = (-3 +- 6i)/5 F x = (-9 +- 12i

Algebra.Com
Question 326366: I need some help with this problem please :
5x^2 + 12x = -9
A x = (-6 +- 3i)/5
B x = (6 +- -3i)/5
C x = (3 +- 6i)/12
D x = (3 +- 6i)/5
E x = (-3 +- 6i)/5
F x = (-9 +- 12i)/5
Any help would be much appreciated !!!

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
5x^2 + 12x = -9
5x^2 + 12x + 9 = 0
a = 5 ; b = 12 ; c = 9
--------------------------
x = [-b +- sqrt(b^2 - 4ac)]/(2a)
---
x = [-12 +- sqrt(144 -4*5*9)]/(10)
---
x = [-12 +- sqrt(-36)]/10
---
x = [-12 +- 6i]/10
---
x = [-6 +-3i]/5
===================
Cheers,
Stan H.
===================
A x = (-6 +- 3i)/5
B x = (6 +- -3i)/5
C x = (3 +- 6i)/12
D x = (3 +- 6i)/5
E x = (-3 +- 6i)/5
F x = (-9 +- 12i)/5

RELATED QUESTIONS

1. (-2-2)(-4-3i)(7+8i) 2. 5i+7i*i 3. (6i)^3 4. 6i*-4i+8 5. -6(4-6i) 6. (8-3i)^2 7.... (answered by harpazo)
Please help me!!!! 3x^2 + 2 1/2 x = -2 A x = {-5 +- i[SQRT(71)}/12 Bx = {5 +-... (answered by solver91311)
For i =square root −1, if 3i(2 + 5i) = x + 6i,then x = ? A. –15 B. 5 C. 5i (answered by jim_thompson5910)
For i = the square root of -1, if 3i (2 + 5i) = x + 6i, then x = ? A. –15 B. 5 C.... (answered by stanbon,josgarithmetic)
3x^2 + 6 3/4 x + 6 3/4 = 1 1/2 x^2 + 2 1/4 x A) x = (-3 +- 3i)/3 B) x = (3 +- 3i)/2 (answered by richwmiller)
3i(2+5i)=x+6i (answered by edjones)
Please help me how to understand this problem: (1/3 + 2/3i) + (1/3 - 5/6i) Thank... (answered by Earlsdon,olayinka003)
5+6i/5+3i (answered by jim_thompson5910)
I have a question. For i= the square root of -1, if 3i(2+5i) = x+6i, then x = A. -15 (answered by josmiceli)