The temperature was 75º. At noon, the temperature increased 7º. By evening, the temperature decreased by 7º. How did the temperature change?

The cash price of a television is $580.the hire-purchase price of the television is $865.the hire-purchase price is an initial deposit of n% of the cash price and 6 equal monthly payments of $120.find the value of n.

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?

Parabolas y=−2x^2 and y=2x^2 +k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.