Answer(s):
d= 4 (D=4) or 4=d (4=D)
Step-by-step explanation: You can solve it in 2 ways.
The [tex]1^{st}[/tex] way:
4d−4 = 5d−8
+4 +4
4d = 5d-4
-5d -5d
-1d = -4
/-1 /-1
d = 4
The [tex]2^{nd}[/tex]
4d−4 = 5d−8
+8 +8
4d+4 = 5d
-4d -4d
4 = 1d
/1 /1
4 = d
Hope this helps. :)