x =

Step-by-step explanation:

m + n + ex = 2m - x ( add x to both sides )

m + n + ex + x = 2m ( subtract m + n from both sides )

ex + x = 2m - m - n = m - n ( factor out x from each term on the left side )

x(e + 1) = m - n ← divide both sides by (e + 1)

x =