how to solve 2[5a-3(4a-b)]-4[8b+5(a-2b)]
there's nothing to solve
If you want to simplify the expression, then it comes out
2[5a-3(4a-b)]-4[8b+5(a-2b)]
2[5a-(12a-3b)]-4[8b+(5a-10b)]
2[5a - 12a + 3b] - 4[8b + 5a - 10b]
2[-7a+3b]-4[5a-2b]
-14a+6b-20a+8b
-34a+14b