Solve each of the following equations for $x$.

1. $\frac { x } { 3 } = \frac { 4 } { 5 }$ 

   Answer (a):

   $x=\frac{12}{5}$

2. $\frac { x } { x + 1 } = \frac { 5 } { 7 }$ 

   Answer (b):

   $x=\frac{5}{2}$

3. $\frac { 6 } { 15 } = 2 - \frac { x } { 5 }$ 

   Hint (c):

   Multiply both sides of the equation by 15 and simplify each term.

   More Help 1(c):

   Be sure you multiply each term, including $2$, by $15$.

   More Help 2(c):

   $6=30−3x$

4. $\frac { 2 } { 3 } + \frac { x } { 5 } = 6$ 

   Hint (d):

   What is the common denominator of $3\ \text{and}\ 5$?

   More Help (d):

   See part (c).