Respuesta :

42=-2d+6 move the constant to the other side (subtract)

36=-2d since -2d is multiplying divide it

-18=d switch sides

d=-18 you're done!

Hope this helps, now you know the answer and how to do it. HAVE A BLESSED AND WONDERFUL DAY! As well as a great rest of Black History Month! :-)  

- Cutiepatutie ☺❀❤