Answer:
x = - 7
Explanation:
From the diagram
NM + ML = NL ( substitute values )
x + 12 + 2x + 20 = 11 ( collect like terms on left side )
3x + 32 = 11 ( subtract 32 from both sides )
3x + 32 - 32 = 11 - 32 ( simplify both sides )
3x = - 21 ( divide both sides by 3 )
x =
, that is
x = - 7