are you providing steps...or just want us to solving showing you what to do?
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3 + 4d - 14 = 15 - 5d - 4d
First, combine like terms on each side of the equals.
-11 + 4d = 15 - 9d
now, move the -11 over to the right by addition
4d = 26 - 9d
now, move the -9d over to the left by addition
13d = 26
now, divide each side by 13
d = 2