215-121

To write 215 as a fraction with a common denominator, multiply by 77.

215⋅77-121

To write -121 as a fraction with a common denominator, multiply by 55.

215⋅77-121⋅55

Multiply 215 and 77.

2⋅715⋅7-121⋅55

Multiply 15 by 7.

2⋅7105-121⋅55

Multiply 121 and 55.

2⋅7105-521⋅5

Multiply 21 by 5.

2⋅7105-5105

2⋅7105-5105

Combine the numerators over the common denominator.

2⋅7-5105

Multiply 2 by 7.

14-5105

Subtract 5 from 14.

9105

9105

Factor 3 out of 9.

3(3)105

Cancel the common factors.

Factor 3 out of 105.

3⋅33⋅35

Cancel the common factor.

3⋅33⋅35

Rewrite the expression.

335

335

335

The result can be shown in multiple forms.

Exact Form:

335

Decimal Form:

0.0857142‾

Evaluate 2/15-1/21