Could you please help me with this exercise? Thanks.

Adding and substracting vectors
Solve for the unknown variables:
(a) (a, b) + (3, 0) = (6, 7)
(b) (11, c) + (d, 5) = (-12, −3)
(c) (5, 5) + (e, 4) = (2, f)
(d) (-1, −3) − (5, g) = (h, 2)

I'll do one of them, they are all the same and very easy

b) (11,c) + (d,5) = (-12,-3)
(11+d , c+5 ) = (-12,-3
so 11+d = -12
d = -23
and c+5 = -3
c = -8