completing the square

[kkhewett]

please help me soolve these two equations
quadratic-completing the square
x^2 + 10x -9 =0 I think I habve tried just about everything and can't get anthing but 63 which does not equal 0
or can you just help me figure out the proper formula to use??

second problem is this
solve using quadritic equation:
3x^2-6x=24
KK

 

[mmm4444bot]

I'm not sure what it is that you do not understand about completing the square because you did not show your work.

Half of 10 is 5, and 5 squared is 25. So, we add and subtract 25 from the polynomial.

x^2 + 10x + 25 - 9 - 25 = 0

(x + 5)^2 - 34 = 0

Now, solve for x.

I'm also not sure what it is that you do not understand about using the Quadratic Formula.

3x^2 - 6x - 24 = 0

Notice how all of the parameters A, B, and C are divisible by 3? So, we can reduce these values by first dividing both sides of the given equation by 3.

x^2 - 2x - 8 = 0

A = 1
B = -2
C = -8

Do you have a textbook? Do you need online references for lessons on completing the square or the Quadratic Formula?

Please show your work, if you want more help.

Cheers ~ Mark