Respuesta :

The measures of angles ADB and BDC add up to the measure of angle ADC:

[tex]134^\circ=(5x+4)^\circ+(7x-2)^\circ[/tex]

[tex]\implies134=12x+2[/tex]

[tex]\implies12x=132[/tex]

[tex]\implies x=11[/tex]

Then

[tex]m\angle BDC=(7\cdot11-2)^\circ=\boxed{75^\circ}[/tex]