Answer:
Explanation:
Step 1: Write out equation
d(-3 + x) = kx + 9
Step 2: Distribute
-3d + dx = kx + 9
Step 3: Subtract dx on both sides
-3d = kx - dx + 9
Step 4: Subtract 9 on both sides
-3d - 9 = kx - dx
Step 5: Factor
-3d - 9 = x(k - d)
Step 6: Divide both sides by k - d