What is the correct answer

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

Which ordered pair is a solution to the system of linear equations? 2x + 3y= 6 –3x + 5y = 10

Is there a direction u in which the rate of change of f(x, y)equals=x squared minus 3 xy plus 4 y squaredx2−3xy+4y2 at p(1,2) equals 14? give reasons for your answer. choose the correct answer below. a. no. the given rate of change is smaller than the minimum rate of change. b. no. the given rate of change is larger than the maximum rate of change. c. yes. the given rate of change is larger than the minimum rate of change and smaller than the maximum rate of change.