Help ASAP i dont remember how to do any of this and need help

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?

These tables represent a quadratic function with a vertex at (0, -1). what is the average rate of change for the interval from x = 9 to x = 10?

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula , what is the temperature in celsius corresponding to r degrees rankine? a. 9/5(c - 273) b. 9/5(c + 273) c. 5/9( c - 273) d. 5/9( c + 273)