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

1. $2+3x$  for  $x=4$

   Hint (a):

   Rewrite the expression, substituting in the known variable.

   Steps (a):

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

   Answer (a):

   $14$

2. $4−5c$  for  $c =- \frac { 1 } { 2 }$

   Hint (b):

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

   Answer (b):

   $6.5$

3. $3d^2−1$ for  $d=−5$

   Step (c):

   $3(−5)^2−1$
   $3(25)−1$
   $75−1$

   Answer (c):

   $74$

4. $−4(r−2)$  for  $r=−1$

   Hint (d):

   Refer to parts (a) and (c).

5. $3(t−12)^2−1$  for  $t=14$

   Hint (e):

   Rewrite the problem, substituting in the known variable and then solve.