(1)若x是方程4-4(x-3)=2(9-x)的解;y是方程6(2y-5)+20=4(1-2y)的解,求2(-3xy+x2)-[2x2-3(5xy-2x2)-xy]的值.
(2)解方程:1.7-2x0.3=1-1.2+2x0.6.