What is the first step in solving the following system of equations? 3 x + y = 23. 8 x + 2 y = 23.

Substitute the value of y from one equation into the other equation.
Solve the first equation for y.
Subtract the second equation from the first equation.
Substitute the value of x from one equation into the other equation.

In one day there are too high tides into low tides and equally spaced intervals the high tide is observed to be 6 feet above the average sea level after six hours passed a low tide occurs at 6 feet below the average sea level in this task you will model this occurrence using a trigonometric function by using x as a measurement of time assume the first high tide occurs at x=0. a. what are the independent and dependent variables? b. determine these key features of the function that models the tide: 1.amplitude 2.period 3.frequency 4.midline 5.vertical shift 6.phase shift c. create a trigonometric function that models the ocean tide for a period of 12 hours. d.what is the height of the tide after 93 hours?