A.
2x + 2¹/₃ = 1
L = 2·(-2/3) + 7/3 = -4/3 + 7/3 = 3/3 = 1
P = 1
L = P
B.
6x - 8 = -4
L = 6·(-2/3) - 8 = -4 - 8 = -12
P = - 4
L ≠ P
C.
3x³+ 1/9 = 1
L = 3·(-2/3)³ + 1/9 = 3·(-8/27) + 1/9 = -8/9 + 1/9 = -7/9
P = 1
L ≠ P
D.
3x² - 1/3 = 1
L = 3·(-2/3)² - 1/3 = 3·4/9 - 1/3 = 4/3 - 1/3 = 3/3 = 1
P = 1
L = P
Liczba (-2/3) spełnia równanie A i D.
