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4A
a 3/7
b 1/7
c 3
d -5/49

4A
a = 1, b = 1, c = -6

4B
a -5/2
b -3/2
c -1
d 2/3

4B
a = 16, b = -4, c = -32, d = 15

4B
α = 2 and k = 2 or α = 8 and k = 1/2

4C
a -2
b -3/2
c ½
d 1
e 1/2

4C
a = 72, b = -102, c = -25, d = 53, e = -12

4C
a 2
b d = -494, e = 420

4D
c 38