The equation is
.
Apply addition property of equality: If a = b then a + c = b + c.
\
(Add 4 to each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Add:
)
Apply addition property of equality: If a = b then
.
(Divide each side by 5)
(Cancel common terms)
(Divide:
)
The solution is
.