Question

What are the exact solutions of x2 − 5x − 7 = 0?

Answer 1

Where are you getting stuck with this problem?

Answer 2

i dont get the whole thing

Answer 3

Do you know what the graph of this function looks like?

Answer 4

what do you mean ?

Answer 5

The solutions are where the graph intersects the x-axis. I was just seeing if you knew (approximately) what those points were. (most computers / calculators will give answers up to 2, 3, .etc decimal places).

Answer 6

a quick way is to probably use the quadratic formula \[x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\]

Answer 7

@heatherm9 Here's a graph of your function.

The function is the blue "u" shaped curve (a parabola).
Where it intersects the x-axis (the one that goes left and right not up and down) are the solutions to the equation you wrote.

Also

x2 means "two times x"
x^2 means "x squred"

These are VERY different. :) (unless x = 2 then they're the same, but for all other numbers, they're different).

I recommend going to http://www.mathtv.com and watching the algebra videos about solving quadratics.

Hope this helps.