HELP!! Plzz I’m in a test and I really need help

The mean temperature for the first 4 days in january was 7°c. the mean temperature for the first 5 days in january was 5°c. what was the temperature on the 5th day?

Line cd passes through points c(1, 3) and d(4, –3). if the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b? –5 –2 1 5

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39