Help just the last problems

Find the sum of 4x^{2} -4+6 and -7^{2} +3x+1

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 3 days later). the pool was open on monday, but it was closed on thursday. the high temperature was 30∘c on monday, but decreased at a constant rate in the next 3 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.

For the inequality |c| < |d| to be true, which of the following must be true?