Can I upgrade my laptop's RAM if it's soldered to the motherboard?

No, if the RAM is soldered to the motherboard, you can’t add or swap it. Some laptops (especially thin ones like MacBooks or ultrabooks) solder everything to save space, while others use standard SO-DIMM slots that you can replace. Check your laptop’s service manual or manufacturer’s site—if they say “soldered” or “onboard,” you’re stuck; if they mention “upgradeable” or “SO-DIMM slots,” you can swap the sticks by matching DDR type and speed.