Answers by visitors named: herbgeorge
What is wrong with just plugging in a zero for the y to get the x intercept? In this case it is 4, the sqrt of 16. What is meant by extent? Do you have a graph to which you are supposed to refer? If not, draw your own.
Goci=foci, the plural of focus.
Notice that the denominators are perfect squares. So, either remember sqrts or just substitute in zeroes to get intercepts. Reiny did not give you the foci for some reason.
If I were you, I would mutiply the bottom left clear through by 2 to get rid of the x's and leave the y's:
2x+5y=3
-2x+6y=-14
2+-2 opposites add up to zero
11y=-11
y=-1
Do the same with the others on the right. -3 as a factor makes the y's go away so you have nothing but x's to do.
-6x+-3y=-9 and 5x+3y=2 Opposite 3's add up to zero.
-x=-7 which is the same as x=7
Introduce a factor that gives you only one variable letter to work with instead of two. Take -x times 2 to get -2x which adds up to zero when added to 2x. Boom, your x's are gone. Solve for y and use whatever y equals to find x back in the original equations. -3y+3y=0 for the other side, so you can knock out the y's. Figure out x. Go back and figure out y based upon x.
The grapah of a quadratic is a parabola, which is a U shaped curve. It might help to sketch this out on a coordinate plane first.