What is the first step to solve the following system of equations using substitution?

[15 points]find the quotient with the restrictions. (x^2 - 2x - 3) (x^2 + 4x + 3) ÷ (x^2 + 2x - 8) (x^2 + 6x + 8)

From the beginning of the day the temperature rose 15 degrees so that by 4 pm it was 87 degrees. what was the temperature at the start of the day

In order to be invited to tutoring or extension activities a students performance 20 point higher or lower than average for the