\
The expression is
.
Addition property of equality:
\If x – a = b, then x – a + a = b + a, or x = b + a.
\
(Add 9to each side
(Additive inverse property:
)
(Add:
)
Check:
\Check the solution by substituting
in the original equation.

(Subtract: – 2 – 9 = –11)
The value of 