Answer:
[tex]1.\ 21y^2-27[/tex]
[tex]2.\ 0.5x^4+9.5[/tex]
Step-by-step explanation:
Solving (1)
[tex]3y^2+3(6y^2-9)[/tex]
Open bracket
[tex]3y^2+3*6y^2-3*9[/tex]
[tex]3y^2+18y^2-27[/tex]
Simplify like terms
[tex]21y^2-27[/tex]
Solving (2)
[tex]0.5(x^4-3)+11[/tex]
Open bracket
[tex]0.5*x^4-0.5*3+11[/tex]
[tex]0.5x^4-1.5+11[/tex]
Simplify like terms
[tex]0.5x^4+9.5[/tex]