\({9 \over 3 x} + {6 \over 3 x} = {15 \over 3 x} = {5 \over x}\)

\({5 \over p} - {8 \over 4 p} = {20 \over 4 p} - {8 \over 4 p} = {12 \over 4 p} = {3 \over p}\)

\({8 \over 9 a} + {5 \over 7 b} = {56 b \over 63 a b} + {45 a \over 63 a b} = {56 b + 45 a \over 63 a b}\)

\(3 - {7 \over 5 a} = {3 \over 1} - {7 \over 5 a} = {15 a \over 5 a} - {7 \over 5 a} = {15 a - 7 \over 5 a}\)

\({4 x \over y} - {3 \over 8 y} = {32 x \over 8 y} - {3 \over 8 y} = {32 x - 3 \over 8 y}\)

\({3 a \over a} = {3 \over 1} = 3\)

\({p \over 6 p} = {1 \over 6}\)

\({8 a \over 10 a} = \frac{4}{5}\)

\({-40 x \over 5 x} = -8\)

\({16 x y \over -28 x z} = -{4 y \over 7 z}\)

\({6 b \over -15 a b} = -{2 \over 5 a}\)

\({-18 x y z \over 2 y z} = -9 x\)

\({3 x y \over y} + {4 x z \over z} = 3 x + 4 x = 7 x\)

\(5 p - {9 \over 7 p} = {5 p \over 1} ⋅ {7 p \over 7 p} - {9 \over 7 p} = {35 p^{2} \over 7 p} - {9 \over 7 p} = {35 p^{2} - 9 \over 7 p}\)

\({7 y \over 8 x} - {3 x \over 9 y} = {63 y^{2} \over 72 x y} - {24 x^{2} \over 72 x y} = {-24 x^{2} + 63 y^{2} \over 72 x y} = {-8 x^{2} + 21 y^{2} \over 24 x y}\)

\({5 \over a} ⋅ -{7 \over b} = -{35 \over a b}\)

\({a \over 2} ⋅ {5 \over b} = {5 a \over 2 b}\)

\({6 \over 5} ⋅ x = {6 x \over 5}\)

\({6 b \over a} ⋅ {a + 2 \over 9} = {6 b (a + 2) \over 9 a} = {2 b (a + 2) \over 3 a} = {2 a b + 4 b \over 3 a}\)

\({5 \over a} : {9 \over b} = {5 \over a} ⋅ {b \over 9} = {5 b \over 9 a}\)

\(-{7 \over 5} : x = -{7 \over 5} : {x \over 1} = -{7 \over 5} ⋅ {1 \over x} = -{7 \over 5 x}\)

\({9 \over 7} : {x + 2 y \over y} = {9 \over 7} ⋅ {y \over x + 2 y} = {9 y \over 7 (x + 2 y)} = {9 y \over 7 x + 14 y}\)

\({4 p \over 9} + {p - 1 \over 7} = {28 p \over 63} + {9 (p - 1) \over 63} = {28 p + 9 (p - 1) \over 63} = {37 p - 9 \over 63}\)