b) aX-Y=Z /: X
a - Y = Z:X /+Y
a = Z : X + Y
c) U+4a=W/ - U
4a = W - U /: 4
a = (W - U) : 4
d) Ba-C=D/ + C
Ba = D + C/ : B
a = (D + C) : B
e) 5p+ar=3 /- 5p
ar = 3 - 5p /: r
a = (3 - 5p) : r
f) mn-6a=b / - mn
-6a = b - mn /: (-6)
a = (b - mn) : - 6
g) -3r+2a=1 /+ 3r
2a = 1 + 3r /: 2
a = (1 + 3r) : 2