To evaluate an expression at a given value means that you substitute the given value anywhere you see the variable. For example, if the expression is:
[tex]x+1[/tex]
and the problem asks you to evaluate the expression at x=9, then we substitute x=9 and get:
[tex]9+1=10.[/tex]
Now, question number 3 asks us to evaluate
[tex](1.42+t)\times u+\frac{0.42}{v},[/tex]
at t=13.5, u=7, and v=6. Therefore substituting the given values we get:
[tex]\begin{gathered} (1.42+13.5)\times7+\frac{0.42}{6}=(14.92)\times7+0.07 \\ =104.44+0.07=104.51. \end{gathered}[/tex]
Answer: 104.51
