Step-by-step explanation:
what is the problem ? just take a deep breath, don't panic and think straight :
1) 12×k, which is usual written as 12k
2) u + 3
3) 1/5 × b = b/5
4) 10 - y
5) (a + 4) / 2
6) you did not say what is n summed with. so, I just designate this by "?".
(? + n) × 4
7) did you mean "take away one sixth from 4" ?
4 - 1/6
this can be simplified, as a whole number can be expressed by x/x (incl. 6/6). so, 4 = 4×6/6 = 24/6.
and so we have
24/6 - 1/6 = 23/6 = 3 5/6
8) d/2, often also written as d:2
9) 7 + v + w
10) the product of what with x ?
I designate this again by "?".
9 + ?x or
9 + ?×x or
9 + ?*x