Question

M = 5(d + k) ; solve for d I put M over 5k would be equal to d I'm not sure if I'm correct

Answer 1

First step we use the distributive method:
m=5d+5k

second step is to isolate d:
subtract 5k
m-5k=5d

now divide (m-5k) by 5 to get d alone
$\frac{m-5k}{5}=d$

last step is to simplify
 $\frac{m}{5}- \frac{5k}{5} =d$ 
to get the answer:
$\frac{m}{5}-k=d$

Answer 2

M=5(d+k)

Distribute the 5
M=5d+5k
-M -M
—————-
0=5d+5k-M
-5d -5d
———————-
-5d=5k-M
—— ——-
-5 -5

d = -k-1/5M