What is - 2m^2-2mn+8-10m+10n+mn+4n^2-5n simplify to

Find like terms and group them

3n and 5n are same and 4n^2 and 4n^2 are same

but 3mn and 5n are not and 3n and 2n^3 are not

group like terms

(-2m^2) + (-2mn+1mn) + (8) + (-10m) + (10n-5n) + (2n^2)

add like terms

(-2m^2) + (-mn) + (8) + (-10m) + (5n) + (2n^2)

-2m^2+2n^2-10m+5n-mn+8 is simplest form