Answer:
A.
Step-by-step explanation:
If R(-2), then x = -2. Just plug in -2 for x. -2^2 - 3(-2) - 1 = 4 + 6 - 1 = 10 - 1 = 9. The answer is 9.
I: 2x+y=5
II:3x+2y=4
start by eliminating y
-2*I: -4x-2y=-10
II: 3x+2y=4
add both equations together
-2*I+II: -4x-2y+3x+2y=-10+4
-1x=-6
x=6
insert x=6 into I:
2*6+y=5
y=5-12
y=-7
so the solution is x=6, y=-7
Angle BOC = 120
PROOF
Angle A + Angle B + Angle C = 180
So, Angle B + Angle C = 120 (Angle A = 60)
Now 1/2 (Angle B + Angle C) = 60
1/2 Angle B + 1/2 Angle C = 60..............i
In triangle BOC
1/2 Angle B + 1/2 Angle C + Angle BOC =180
(BO and CO are angle bisectors)
Or 60 + Angle BOC = 180 (using i)
OR ANGLE BOC = 120
200-144=56
56/2=28
Neil is 28