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
the first option is the answer
Step-by-step explanation:
4c + 6a <= 120 [building hours]
4c + 4a <= 100 [testing hours]
4 * 20 + 6 * 6 <= 120
80 + 36 <= 120
116 <= 120
true, they have enough building hours
4 * 20 + 4 * 6 <= 100
80 + 24 <= 100
104 <= 100
false, they won't have enough testing hours
the first option is the answer
Answer:
A. 72cm
Step-by-step explanation:
Figure a is a convex pentagon, a convex pentagon is a pentagon that does not have an internal angle greater than

An easier thing to remember is that it does not have an angle pointing inwards like b, none of its angles/edges point toward the shape/inside
36 divided by nie would be 4
Answer: c. H
Explanation: 37+45+35+29+52=198
198/5=39.6
Hope this helped! :)