MN = √((0 - 4)² + (2 - (-2))² + (-2 - 0)²) = √(16 + 16 + 4) = 6
NK = √((-2 - 0)² + (-4 - 2)² + (2 - (-2))²) = √(4 + 36 + 16) = √56 = 2√14
MK = √((-2 - 4)² + (-4 - (-2))² + (2 - 0)²) = √(36 + 4 + 4) = √44 = 2√11
PΔMNK = 6 + 2√14 + 2√11
1)
2x - 3 (4 - x) = 5 - (x - 1)
2x - 12 + 3x = 5 - x + 1
6x = 18
x = 3
2)
5x - 6 (2x + 7) = 13 - (x + 1)
5x - 12x - 42 = 13 - x - 1
-6x = 54
x = -9