I'm not going to do the entire question, but I'll do the first part.
For the first part, you have to set up an inequality. Use context clues, such as
no more than (the one used in this sentence) to figure out what the symbol should be for the inequality.
In this case, because it is NO MORE THAN 6400, it would be:
6400

250r + 475p
where r represents the # refrigerators, and p represents the # pianos
Now that you have the equation, make the graph, then for the 3rd part, plug in 12 and 8 to r and p to see if it keeps the inequality true.
Hope this helps! :)
Answer:
Step-by-step explanation:
6 more than a number is 36: x+6=36
36 more than a number is 6: x+36=6
6 times a number is 36: 6x=36
Okay, so since the discount is 60% of the price and it comes out to $2.8, we are going to form the following expression, where x is the original price.
60% of x = 2.8
Simply means: 60/100 * x = 2.8
You solve for x, which comes out to $4, which is your original price.
The estimated portion of light bulbs that last more than 500 hours will be
x=∑xn=224/430=0.521=52.1%