Question

2=a+b+c -2=a-b+c 3=4a+2b+c

Answer 1

a = b+c-2

a = c-b+2

b+c-2 = c-b+2

移去c b-2 = 2-b

∴ b = 2

将b 带入方程式1

得到

2 = a+2+c

∴ a = -c

∴ 3 = -4c +4 +c

∴ c = 1/3

∴ a = -1/3