The equation is .

Apply addition property of equality: Add to each side.

Apply commutative property of addition: a + b = b + a.

                 (Apply additive inverse property: )

To add the fractions denominators must be equal.

Find the least common denominator (LCD).

Multiples of 15: 15,30,45,60,.....

Multiples of 5: 5,10,15,20,.........

The least common multiple of 15 and 5 is 15.

Rewrite each fraction with a common denominator of 15.

                     (LCM is 15)

                         (Add: 2 + 3 = 5)

Apply multiplication property of equality: Multiply each side by 9.

                     (Cancel common terms)

                            (Multiply: )

                                 (Divide: )

Apply division property of equality: Divide each side by negative 4.

                                (Cancel common terms)

Check:

To check the solution, substitute in original equation.

                   (Multiply: )

To add the fractions denominators must be equal. \ \

Find the least common denominator (LCD).

Multiples of 5: 5,10,15,20,25,.........

Multiples of 3: 3,6,9,12,15,18,21,.........

The least common multiple of 3 and 5 is 15.

Rewrite each fraction with a common denominator of 15.

\ \

                     (LCM is 15)

                            (Add: )

Compare the values, the equation is true.

The value of a is .