( x+y)² + 2(x+y)×(x-y)+(x-y)²

The linear combination method is applied to a system of equations as shown. 4(.25x + .5y = 3.75) → x + 2y = 15 (4x – 8y = 12) → x – 2y = 3 2x = 18 what is the solution of the system of equations? (1,2) (3,9) (5,5) (9,3)

Can someone me with these two circle theorem questions asap?

Determine the standard form of the equation of the line that passes through (-2,0) and (8,-5)