Question

-3a5+4a3+7a5-10a3+12a

Answer 1

$\displaystyle\bf\\-3a^{5} +4a^{3} +7a^{5} -10a^{3} +12a=(-3a^{5}+7a^{5} )+(4a^{3} -10a^{3} )+12a=\\\\\\=4a^{5} -6a^{3} +12a$