=2(x？ -6x)+3

=2[(x？ -6x+3？ )-3? ]+3

=2(x-3)？ - 18+3

=2(x-3)？ - 15.

So, the quadratic function y=2x? The symmetry axis of-12x+3 image is the straight line x=3, and the vertex coordinate is (3,-15).

(2)y=-5x？ +80x-3 19 The symmetry axis of the image is a straight line x=8, and the vertex coordinate is (8, 1).

(3)y=2(x- 1/2)(x-2)，

Finishing, y=2x? -5x+2，

The formula y=2(x? -5/2 times) +2

=2[x？ -5/2 x+(5/4)？ -(5/4)? ]+2

=2(x-5/4)？ -25/8+2

=2(x-5/4)？ -9/8.

Therefore, the symmetry axis of the image of the quadratic function y=2(x- 1/2)(x-2) is the straight line x=5/4, and the vertex coordinates are (5/4, -9/8).

(4)y=3(2x+ 1)(2-x)，

Finishing, y=-6x? +9x+6，

The formula y=-6(x? -3/2 x)+6

=-6[x？ -3/2 x+(3/4)？ -(3/4)? ]+6

=-6(x-3/4)？ +27/8+6

=-6(x-3/4)？ +75/8

Therefore, the image with quadratic function y=3(2x+ 1)(2-x) has a straight line x=3/4 and its vertex coordinates are (3/4, 75/8).

Bian Xiao suggested: