How many solutions does the following system of linear equations have?

y=-6x+6
y=5x+1

Can someone me and plz do the problem

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Which statement is true about the extreme value of the given quadratic equation? a. the equation has a maximum value with a y-coordinate of -21. b. the equation has a maximum value with a y-coordinate of -27. c. the equation has a minimum value with a y-coordinate of -21. d. the equation has a minimum value with a y-coordinate of -27.