SOLUTION: solve by factoring: 16x^2 - 81 = 0 solve by completing the square: 6x - 2 = x^2 solve by the quadratic formula: 8x + 4 = 2x^2 (PS: Please show how you worked it o

Question 142864: solve by factoring:
16x^2 - 81 = 0

solve by completing the square:
6x - 2 = x^2

solve by the quadratic formula:
8x + 4 = 2x^2

(PS: Please show how you worked it out. I have been having mojor problems with these kinds of questions. Thanks.)
Answer by nabla(475) (Show Source): You can put this solution on YOUR website!
16x^2 - 81 = 0
(4x+9)(4x-9)=0
x= +/- (9/4)
.
.
.
6x - 2 = x^2
0=x^2-6x+2
0=x^2-6x+9+2-9
7=(x-3)^2
+-sqrt(7)=x-3

.
.
.
8x + 4 = 2x^2
0=2x^2-8x-4

x=2 +/- 4sqrt(6)/4
x=2 +/- sqrt(6)
RELATED QUESTIONS
2x^2-x-21=0... solve by factoring,completing the square, and the quadratic formula.... (answered by rwm)

Solve by completing the square and quadratic formula: 1.) x^2-6x+8=0... (answered by mananth)

1) Solve the quadratic equations by factoring: 5x� = 125 2) Solve the quadratic... (answered by checkley71)

solve x^2-16x+32=0 by completing the... (answered by rapaljer)

Solve by completing the square. x^2 � 16x + 63 = 0 (answered by bucky)

Solve by completing the square. x^2 � 16x + 63 =... (answered by edjones,Fombitz)

Using the quadratic equation x^2 - 4x - 5 = 0, perform the following tasks: Solve by... (answered by ikdeep)

Solve by completing the square: x^2 + 6x + 4 = 0 (answered by jim_thompson5910)