Step-by-step explanation:

Answer:
99
Step-by-step explanation: Use PEMDAS
12+8 = 96
96+6 = 102
102-3 = 96
Hope this helped!
Answer:
Step-by-step explanation:it is infinite solution because 15 is equal to 15 if it was like 15=13 it is no solution
Answer:
1. 600 watts
2. 35640 J
3. 55%
4. 20 J
5. The cost of running the fire is 8p.
Step-by-step explanation:
1. Energy = 36 000 J , t = 1 minute = 60 seconds
Power = 
= 
= 600 watts
2. Power = 
⇒ work done = Power × time
= 99 × 360
= 35640 J
3. Efficiency = (Output / Input) × 100
=
× 100
= 55%
4. Work done = Force × distance
= 5 × 4
= 20 J
5. Given that 1 KWh cost 2p, Power = 4 KW and time = 4 hours.
Power = 
Energy = Power × time
= 4 × 4
= 16 KWh
The cost of running the fire = 
= 8p