Simplifying the expressions we have
13)
[tex]\begin{gathered} 0.8x+0.3x+2 \\ x(0.8+0.3)+2 \\ 1.1x+2 \end{gathered}[/tex]
14
a) YES
[tex]3z+2z=5z\to Yes[/tex]
b) NO
[tex]\begin{gathered} (8x-8x)-y=0x-y=-y \\ -y\ne0\to NO \end{gathered}[/tex]
c) NO
[tex]\begin{gathered} 9.1+4.5a-2.5a=9.1+2a \\ 9.1+2a\ne11.1a\to NO \end{gathered}[/tex]
d) NO
[tex]\begin{gathered} -7yx3-3=-3(7yx+1) \\ -3(7yx+1)\ne0\to NO \end{gathered}[/tex]
e) YES
[tex]\begin{gathered} y-6(3)=y-18 \\ y-18=y-18\to\text{YES} \end{gathered}[/tex]