We have [tex]a=3,b=-2[/tex] and expression [tex]-a+6b[/tex].
To evaluate expression substitute [tex]a[/tex] and [tex]b[/tex] with their values to get [tex]-3+6\cdot(-2)[/tex]. Then simplify the expression starting with multiplication to get [tex]-3-12[/tex] and now simply subtract get value of expression [tex]\boxed{-15}[/tex].
Hopefully this will help.
