We know: The sum of measures of angles in a triangle is equal 180°.
Therefore we have the equation:
[tex](x+6)+(3x-16)+x=180\\\\x+6+3x-16+x=180\qquad|\text{combine like terms}\\\\(x+3x+x)+(6-16)=180\\\\5x-10=180\qquad|\text{add 10 to both sides}\\\\5x=190\qquad|\text{divide both sides by 5}\\\\x=38\\\\m\angle M=(3x-16)^o\to m\angle M=(3(38)-16)^o=(114-16)^o=98^o[/tex]
Answer: m∠M = 98°
