Hackers often use a botnet to launch a or a bombardment of network traffic or messages designed to overload a server.

distributed denial-of-service (DDoS)
       
A distributed denial-of-service attack is where an attacker has multiple systems flood a target system consuming bandwidth and resources on the target system. Because of this, legitimate users of the target system are generally unable to access the system. The multiple systems used to launch the attack are frequently botnets that have been previously compromised.

If you see that 3x-3 and set it equal to x+7 then you will get this,

3x-3=x+7

Now solve for X. You will get 5.

Then you plug five in and get 12 For both sides and then multiply 12 by 4 and get 48.

You answer is 48.

Hope this helps you.