B and C are correct.
A circle has 360°. 2/3 of that circle is given by
2/3(360) = 720/3 = 240°.
Stu takes half of this, so his piece will have 240/2 = 120°.
He splits the remainder of it between his 2 sisters; 240-120 = 120° left; 120/2 = 60° for each sister's piece.
You can plug -x - 1 for y in the first equation
2x - (-x - 1) = 10
2x + x + 1 = 10
Combine
3x = 9
Divide
x = 3
Plug 3 for x in any equation ( I'll use th second equation )
y = - (3) - 1
y = - 3 - 1 = -4
x = 3 ; y = -4
(3, -4)
1.291
1.251
1.341
1.331
1.321
1.311
1.281
1.271
1.261
400x to the power of 2 + 480x + 144
