Answer:
d = 3
Step-by-step explanation:
(7d+3)/4 = 6
Multiply each side by 4
(7d+3)/4*4 = 6*4
(7d+3) = 24
Subtract 3 from each side
7d+3-3 = 24-3
7d = 21
Divide by 7
7d/7 = 21/7
