Can you help me? Nobody could asnwer these!?

Question

If the answer is irrational, please give the answer as a simplified radical, not as a rounded decimal.

x^2 + 3x = 12




The following equation is in Standard form.

Put the equation in General form by completing the square.

Tell the vertex of the parabola.

Please use ^ for exponents.

f(x)= x^2 - 4x + 7

Answer 1

yes u right nobody could asnwer these

Answer 2

....... Are you Samantha S?

Do you want the answers? Here are the answers.

x^2 + 3x = 12
Subtract 3x from both sides.
x^2 = 12 - 3x
Put both sides in a square root.
sqrt(x^2) = sqrt(12 - 3x)

Square root of x^2 equals x.

So, x = sqrt(12 - 3x).



I'm having a tiny bit of trouble with the function, so I'll get back to you on that.

ADD: The answer to the second equation was staring me in the face. I feel like an idiot.

To complete the square, take what's common between all three and put it outside the parentheses. In this case,

(x-2)((x-2) +3). If you work it out, you're left with f(x) = x^2-4x+4+3.

Now turn it into an equation for a parabola: (y-k) = (x - h)^2. Substitute "y" for "f(x)", and you get k=3 and h=2.

The vertex is (3,2).

Others have already solved this.

Answer 3

The first one can't be factored, so you'll have to go with completing the square or the quadratic formula.

For the second one, replace f(x) with y, and you get
y = x^2 - 4x + 7
y - 7 = x^2 - 4x

Now use completing the square on the right side. You should end up with (y - 3) = (x - 2)^2. You can easily determine the vertex by looking at this, because it's in the form of (y-k) = (x-h)^2

Answer 4

x^2+3x-12=0 so x=((-3+-sqrt(57))/2 No further simplification

f(x) = (x-2)^2 +3 vertex(2,3)

Answer 5

x^2 + 3x + 9/4=57/4
(x+3/2)=sqrt(57)/2
x= (sqrt(57) -3)/2