Respuesta :

4d+6= 42
⇒ 4d= 42-6
⇒ 4d = 36
⇒ d= 36/4
⇒ d= 9

The final answer is d=9~
4d + 6 = 42
4d +(6-6) = (42 - 6)
4d = 36 
divide both sides by 4
d = 9