Follow order of operations.
Distribute what is in the parentheses.
4[6a^2 -2ab +3ab] + 5[3ab + 6b^2 -4ab]
Combine like terms in the brackets.
4[6a^2 + 3ab] + 5[-1ab + 6b^2]
Distribute the 4 and the 5.
24a^2 + 12ab -5ab + 30b^2
Combine like terms.
24a^2 +7ab + 30b^2
That's your final answer:
24a^2 +7ab + 30b^2
