You haven't listed the possible solutions, so in the immediate present I can help only by suggesting that you try solving this system and checking your own answers thru subst. into the given equations.
Please be sure to use "^" to indicate exponentiation, as shown below:
<span>4x2 + 9y2 = 72 should be 4x^2 + 9y^2 = 72 (this is the eq'n of an ellipse) x - y2 = -1 should be x - y^2 = -1 (this is the equation of a parabola)
We must eliminate either x or y. I will solve the 2nd equation for y^2 and subst. the result into the first eq'n.:
We must solve this quadratic equation to obtain the x-coordinates of possible solutions of the original system of equations. -9 plus or minus 33 After some work, we get x = ------------------------------ 8
So x = 24/8 = 3, or x = -42/8 = -5 1/4 or -21/4
Check out x=3. We already have the relationship y^2 = x+1. If x = 3, then y^2 = 3+1 = 4, and y is plus or minus 2.
Two possible solutions of the original set of equations are thus (3,2) and (3,-2). You MUST check both solutions thru substitution to determine whether they satisfy the original equations or not.
