A mixed number is an addition of its whole and fractional parts.

Add and .

Write as a fraction with a common denominator.

Combine the numerators over the common denominator.

Add and .

Divide by .

Multiply the numerator by the reciprocal of the denominator.

Factor out of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Simplify (21/1)÷1 3/4