I don't know what to do for this question. There are two i already did the second one its the one i circled I don't get. Please if u can show me step by step.

X2 + y 2 = 36 x + y = 6 solve the system of equations.

Benjamin is making bow ties. how many 1/2yards lomg bow ties can he make if he has 18 feet of fabric?

Find the equation of the ellipse with the following properties. the ellipse with foci at (0, 6) and (0, -6); y-intercepts (0, 8) and (0, -8).edit: the answer is x^2 over 28 + y^2 over 64 = 1