Step 1. Multiply both sides by cx+d
ax+d = e (cx+d)
Step 2. Distribute
ax+b = ecx + ed
Step 3. Subtract b from both sides
ax = ecx + ed - b
Step 4. Subtract ecx from both sides
ax - ecx = ed - b
Step 5. Factor our x from the right side
x(a-ec) = ed - b
Step 6. Divide both sides by a-ec
x = (ed-b) / (a-ec)
