We have
[tex]3\mleft(a+2b\mright)+4\mleft(b+5a\mright)[/tex]the distributive property is
[tex]x(y+z)=xy+xz[/tex]so we will expand the polynomials given using the distributive property above
[tex]3\mleft(a+2b\mright)+4\mleft(b+5a\mright)=3a+6b+4b+20a[/tex]we sum similar terms
[tex]23a+10b[/tex]___________________________________________
we have
[tex]3\mleft(a+2b\mright)+4\mleft(b+5a\mright)[/tex]in order to simplify the expression, we need to the multiplication 3(a+2b) and 4(b+5a) using the distributive property
[tex]3(a+2b)=3a+3(2b)=3a+6b[/tex][tex]4\mleft(b+5a\mright)=4b+4(5a)=4b+20a[/tex]we sum the results obtained
[tex]3a+6b+4b+20a[/tex]then to simplify we sum the similar terms
[tex]23a+10b[/tex]