a) q + 35 = 78 (subtract 35 from 78)
q = 43
b) 200 + x = 450 (subtract 200 from 450)
x = 250
c) k - 68 = 72 (add 68)
k = 140
d) 437 - m = 25 (you can do this in one step, but add m to other side or divide everything by -1 to get m pos)
m + 25 = 437 (subtract 25)
m = 412
