Petra started with a number added 3 multiplied the result by 4 subtracted 6 and multiplied that result by 3 her final answer was 90 what did she begin with?

I'm so close to finishing all these.

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.

What is the measure of angle x? answer