=( 15-7-2)+ 1/6-( 1/5+4/5)

=6- 1+ 1/6

=3 1/6

Score calculation method:

Law of multiplication of fractions: Fractions are multiplied by fractions, molecules are multiplied by molecules, denominator is multiplied by denominator, and fractions can be reduced first.

Steps to share:

1, first find the simplest common denominator of the denominator of the original fraction (formula);

2. According to the basic properties of the fraction (formula), the original fraction (formula) is changed to a fraction (formula) with the simplest common denominator as the denominator.

Steps to reduce:

1, numerator and denominator decomposition factor.

2. Find the common factor of numerator and denominator.

3. Exclude non-zero common factors.

If the greatest common divisor of numerator and denominator can be seen quickly, it is easier to divide by their greatest common divisor directly.