someone please help with these three questions
[tex]26)\ \underline{\underline{0.5b^{2}}}[/tex]
[tex]27)\ \underline{\underline{6x + 7}}[/tex]
[tex]28)\ \underline{\underline{30 + 3x^{2}}}[/tex]
In questions 27 and 28, the unknown is called x.