(3•y+5•y)•18=144

Solve for y:

• Combine like terms: 3y + 5y = 8y
• So (3y + 5y) · 18 = 8y · 18 = 144
• 8y · 18 = 144 → 144y = 144
• Divide by 144: y = 1

Check: (3·1 + 5·1)·18 = (3 + 5)·18 = 8·18 = 144. ✔

Answer: y = 1