Step-by-step explanation:
[tex]m\angle {ADC}=134°[/tex]
According to the diagram
[tex]\angle {ADB}+\angle{BDC}=\angle{ADC}[/tex]
[tex]\longrightarrow\sf 5x+4+7x-2=134 [/tex]
[tex]\longrightarrow\sf 12x+2=134 [/tex]
[tex]\longrightarrow\sf 12x=134-2 [/tex]
[tex]\longrightarrow\sf 12x=132 [/tex]
[tex]\longrightarrow\sf x=\dfrac {132}{12}[/tex]
[tex]\longrightarrow\sf x=6 [/tex]
[tex]m\angle{BDC}=7x-2=7×6-2 =40°[/tex]
