Read the Math Notes box for this lesson. Then evaluate each expression below.  

1.  For $y=2+3x$ when $x=4$, what does $y$ equal?

   Hint (a):

   Rewrite the expression, substituting in the known variable.

   Steps (a):

   $y=2+3(4)$
   $y=2+12$

   Answer (a):

   $y=14$

2.  For $a=4−5c$ when $c=-\frac{1}{2}$, what does $a$ equal?

   Hint (b):

   See part (a) for a strategy to evaluate this expression. Remember to pay attention to negative signs.

   Answer (b):

   $a=6.5$

3.  For $n=3d^2−1$ when $d=−5$, what does $n$ equal?

   Hint (c):

   Rewrite the expression, substituting in the known variable.

   Steps (c):

   $n=3(−5)^2−1$
   $n=3(25)−1$
   $n=75−1$

   Answer (c):

   $n=74$

4.  For $v=−4(r−2)$ when $r=−1$, what does $v$ equal?

   Hint (d):

   Refer to parts (a) and (c).

5.  For $3+k=t$ when $t=14$, what does $k$ equal?

   Hint (e):

   Rewrite the problem, substituting in the known variable and then rearrange the problem to make it equal to the unknown variable.