Please help me please

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 33 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 33 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.

Me asap on # : explain how factoring a trinomial, ax^2+ bx+ c, when a does not equal 1 different from factoring a trinomial when a = 1.

X+ y = 5 ; x - y =3 solve using linear combination