qui est fort en maths pour completer un tableau

1/
a:b = -5/4
(-b) : c = -4/-4 = 1
c : (-a) = -4 /5

2/
a:b =  -2.5/-1 = +2.5
(-b) : c = -(-1) /2 = 1/2
c : (-a) = 2 / -(-2.5) = 2/2.5

3/
a:b = 8/-4 = -8/4 = -2
(-b) : c = -(-4) : -0.5 = +4 / -0.5 = - 8
c : (-a) = -0.5 / -8 = 0.5/8 = 0.0625

4/
a:b = - 2.4 /-1.2 = +2
(-b) : c = -(-1.2) / -2.4 = +1.2 / -2.4 = -0.5
c : (-a) = -2.4 / -(-2.4) = -2.4 / +2.4 = +1