Rational Expressions 151
Complex Fractions
A complex fraction is a fraction that has fractions in its numerator, denomi-
nator, or both. One way you can simplify a complex fraction is to interpret
the fraction bar of the complex fraction as meaning division.
Problem Simplify
11
11
xy
x y
+
–
.
Solution
Step 1. Write the complex fraction as a division problem.
11
11
x y
xy
+
–
= +
⎛
⎝
⎛⎛
⎝⎝
⎞
⎠⎟
⎞⎞
⎠⎠
÷
⎛
⎝⎜
⎛⎛
⎝⎝
⎞
⎠⎟
⎞⎞
⎠⎠
(^11) + 11
xy x–y
Step 2. Perform the indicated addition and subtraction.
=
⎛ +
⎝⎜
⎛⎛
⎝⎝
⎞
⎠⎟
⎞⎞
⎠⎠
÷⎛
⎝⎜
⎛⎛
⎝⎝
⎞
⎠⎟
⎞⎞
⎠⎠
yx+
xy
yx−
xy
Step 3. Multiply by the reciprocal of the divisor.
=
( + )
⋅
( )
yx+
xy
xy
yx−
=
( + )
⋅
( )
yx+
xyxy
xyxy
yx−
=
( + )
( )
yx+
yx−