Answer:
D, m<4 is 137°
Step-by-step explanation:
The answer would be D, because m<4 would be supplementary with the angle that's 43 degrees. Supplementary angles add up to 180, so this could be found through the following equation.
x + 43 = 180
x would represent <4
You would now subtract 43 from both sides.
x = 137
identity used is
x³ + y³+ z³– 3xyz = (x + y + z) (x² + y² + z² – xy – yz – zx).
then use
(x+y+z)² = x²+y²+z²+2(xy+yz+xz)
225= 83 + 2(xy+yz+xz)
xy+yz+xz = (225-83)/2
xy+yz+xz= 142/2
xy+yz+xz= 71
ok
now use identity
x³ + y³+ z³– 3xyz = (x + y + z) (x² + y² + z² – xy – yz – zx).
now
x³ + y³+ z³– 3xyz = 15 (83 – xy – yz – zx).
= 15[83 - (71)]
= 15×12
=180
