25.b-a

26. The original formula =X(X+2)(X- 1), so X 1=0, X2=-2, X3= 1.

27.- 14x 3

28.Y=3/2X-3

29.(X-3)？ +(Y+3)？ =9 Is this question a circle with a center of (3, -3) and a radius of 3? Your target value is an ellipse. .