Can someone help me out with these two problems and show work please !!

Answer :
( 6 y^4 + 3 y^2 -7) - (12 y^4 - y^2 + 5)
Step-by-step explanation:
(6 y^4+ 3 y^2-7) - (12 y^4 - y^2 + 5 )
=6 y^4 +3 y ^2 - 7 - 12 y^4 + y^2 - 5
=6 y ^4 - 12 y ^4 +3 y ^2 + y ^2 - 7 -5
= -6 y ^4 + 4 y ^2- 12
Hope this helps!