I have "Write an equation for each problem. Then solve the equation. The opposite of a number is -9. What is the number? I know the opposite is 9 but I don't understand how to make this an equation

Write the system of equations represented by the matrix. 0 1 2 4 -2 3 6 9 1 0 1 3

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.

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?