Explain please!! 12. A shipment of TV sets, some weighing 30 kg each and the other weighing 50 kg each, has a total weight of 220 kg. If there
are 20 TV sets all together, how many weigh 50 kg and how many weigh 30 kg?
A. 6 weigh 50 kg and 14 weigh 30
B. 15 weigh 50 kg and 5 weigh 30.
C. 2 weigh 50 kg and 18 weigh 30
D. 14 weigh 50 kg and 6 weigh 30
E. 4 weigh 50 kg and 16 weigh 30
F. 11 weigh 50 kg and 9 weigh 30

D

Step-by-step explanation:

Let a be the number of TV sets that weight 30 kg and let b be the number of TV sets that weigh 50 kg.

So, all together, they have a total weight of 880. In other words:

And, there are 20 TV sets all together. Thus:

This is a system of equations. Solve by substitution. Subtract b from both sides in the second equation:

Substitute this into the first:

Distribute:

Subtract 600 from both sides:

Combine like terms:

Divide both sides by 20:

So, there are 14 TV sets that weight 50 kg.

Plug this in for the second equation to solve for a:

Plug in 14 for b:

Subtract 14 from both sides:

Therefore, there are 6 TV sets that weigh 30 kg and 14 TV sets that weigh 50 kg.

Our answer is D :)

d) -1

step-by-step explanation:

i will pick c put check it over to be sure

step-by-step explanation: