How do you get it? I've tried for 30 minutes now...
Yes I do know substitution, plus add, and the third way to find intersections.
Not a bad effort. Now, you don't want to end up with your last line unless you have a 0 on the right hand side as that allows you to equate each factor equal to 0 which we don't have here.
What you should do is try to get your expression in the form of a quadratic ( ). The 0 is important as this is the key for using the quadratic formula or to factor for the reason mentioned above:
(divided both sides by 2)
Can you see what to do now?
Are you familiar with solving quadratic equations? There are a few methods you can use:
First, you can try factoring:
Next, if you can't figure out how to factor the expression, or if the expression is simply too messy to easily factor, you can use the quadratic formula, , where are the coefficients of the 2nd-degree, 1st-degree, and constant terms, respectively.
In this case, we have
So, in the formula, .
Alternatively, you can complete the square. For example:
I hope that helps!
Edit: Beaten by o_O! I'm too slow with my LaTeX!
Ah, here's a more harder question:
4x+y+11=0 and (x-5)^2+(y-3)^2=16
What do I do to solve this question...? I'm clueless on what ot do next.
Here's what I did:
(x-5)^2 + (-11-4x-3)^2 = 16
x^2-10x+25+(-14-4x)^2 = 16
x^2-10x+25 + 196 + 16x^2 + 112x = 16
17x^2+102x+221-16 = 16-16
>>Imaginary. What do I do...? THis is all my work.