\({3 \over 9 p} - {2 \over 9 p} = {1 \over 9 p}\)

\({6 \over a} - {9 \over 4 a} = {24 \over 4 a} - {9 \over 4 a} = {15 \over 4 a}\)

\({2 \over 4 x} + {7 \over 8 y} = {4 y \over 8 x y} + {7 x \over 8 x y} = {4 y + 7 x \over 8 x y}\)

\(6 - {8 \over 5 a} = {6 \over 1} - {8 \over 5 a} = {30 a \over 5 a} - {8 \over 5 a} = {30 a - 8 \over 5 a}\)

\({4 x \over y} + {2 \over 3 y} = {12 x \over 3 y} + {2 \over 3 y} = {12 x + 2 \over 3 y}\)

\({2 a \over a} = {2 \over 1} = 2\)

\({p \over 7 p} = {1 \over 7}\)

\({9 a \over -12 a} = -\frac{3}{4}\)

\({-28 x \over -4 x} = 7\)

\({-9 x y \over 21 x z} = -{3 y \over 7 z}\)

\({35 y \over -45 x y} = -{7 \over 9 x}\)

\({24 x y z \over -3 y z} = -8 x\)

\({3 a b \over b} - {4 a c \over c} = 3 a - 4 a = -a\)

\(9 p + {8 \over 5 p} = {9 p \over 1} ⋅ {5 p \over 5 p} + {8 \over 5 p} = {45 p^{2} \over 5 p} + {8 \over 5 p} = {45 p^{2} + 8 \over 5 p}\)

\({3 b \over 6 a} + {9 a \over 7 b} = {21 b^{2} \over 42 a b} + {54 a^{2} \over 42 a b} = {54 a^{2} + 21 b^{2} \over 42 a b} = {18 a^{2} + 7 b^{2} \over 14 a b}\)

\({7 \over x} ⋅ {2 \over y} = {14 \over x y}\)

\({a \over 8} ⋅ -{4 \over b} = -{4 a \over 8 b} = -{a \over 2 b}\)

\({8 \over 5} ⋅ x = {8 x \over 5}\)

\({3 b \over a} ⋅ {a - 8 \over 9} = {3 b (a - 8) \over 9 a} = {b (a - 8) \over 3 a} = {a b - 8 b \over 3 a}\)

\({8 \over a} : {4 \over b} = {8 \over a} ⋅ {b \over 4} = {8 b \over 4 a} = {2 b \over a}\)

\({2 \over 3} : p = {2 \over 3} : {p \over 1} = {2 \over 3} ⋅ {1 \over p} = {2 \over 3 p}\)

\({1 \over 6} : {x - 8 y \over y} = {1 \over 6} ⋅ {y \over x - 8 y} = {y \over 6 (x - 8 y)} = {y \over 6 x - 48 y}\)

\({x \over 4} + {x + 5 \over 9} = {9 x \over 36} + {4 (x + 5) \over 36} = {9 x + 4 (x + 5) \over 36} = {13 x + 20 \over 36}\)