Year 10 maths problem ?

Question

-x(squared) +6x +2=0?

what is x? thanks. also please show working out

Answer 1

   ax²+bx+c=0

where

   a=-1

   b=6

   c=2

x = [-b ± √(b²-4ac)] / (2a)

   = [-(6) ± √((6)² - 4(-1)(2))] / 2(-1)

   = [-6 ± √(44)] / -2

   = [-6 ± 2√11] / -2

   = -3 ± √(11)

   = 3 ± 3.317

x₁ = 3 + 3.317 = 6.317

x₂ = 3 - 3.317 = -0.317

Answer 2

-x^2 + 6x + 2 = 0

(multiply by -1)

x^2 - 6x - 2 = 0

At this point you'll need to use the quadratic formula to solve it.

x = (6 +/- sqrt(36 +8))/2

= (6 +/- sqrt(44))/2

= 3 +/- sqrt(11)

Answer 3

looks hard

Answer 4

the equation is the same as

x^2-6x - 2 = 0

using quadratic formula

  x = 3 + sqrt. 11 & 3 - sqrt. 11

Answer 5

I would use the quadratic formula x = [-b ± sqrt(b² - 4ac)]/(2a).  To use the quadratic formula, the equation must be in this form: ax² + bx + c = 0.

a = -1, b = 6, c = 2

x = [-6 ± sqrt(6² - (4 * -1 * 2)]/(2 * -1)

x = [-6 ± sqrt(36 + 8)]/(-2)

x = [-6 ± sqrt(44)]/(-2)

x = [-6 ± sqrt(4 * 11)]/(-2)

x = [-6 ± 2sqrt(11)]/(-2)

x = (-6/-2) ± [2sqrt(11)]/-2

x = 3 ± sqrt(11)

Answer 6

Multiplying though by -1 gives

x^2 - 6x - 2 = 0

There's no way to factor this, since the only factors of 2 are 1 and 2, an there's no way to add or subtract 1 or 2 to get 6.  So use the quadratic formula or completing the square.

Go here to learn about it:

http://mathforum.org/library/drmath/view...

Answer 7

the * is squared

-x* + 6x +2= 0

-x* +6x + (6/2)* = -2 + (6/2)*

-x* + 6x + (3)* = 7

(-x + 3)* = 7

(-x + 3) = square root 7

-x = -3 plus or minus square root 7

then u could maybe put them over the minus and cancel it out?