1)4/9-5/12=1/36
2)3/8-4/9=-5/72
3)1/36:(-5/72)=-2/5
-2/5=-0,4
1). (x-10)*(x^2+10x+100)-x^3=x^3-1000-x^3= -1000; 2). 216-(a-6)*(a^2-6a+36)=216-a^3-216= -a^3.