What makes a regression line a good fit for the data in a scatter plot and how can we tell from the residual plot?

If g(x) is an odd function, which function must be an even function?

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled

Solve each quadratic equation by factoring and using the zero product property. 10x + 6 = -2x^2 -2