\({5 \over 7 a} - {3 \over 7 a} = {2 \over 7 a}\)

\({7 \over x} - {2 \over 4 x} = {28 \over 4 x} - {2 \over 4 x} = {26 \over 4 x} = {13 \over 2 x}\)

\({2 \over 4 p} + {6 \over 3 q} = {6 q \over 12 p q} + {24 p \over 12 p q} = {6 q + 24 p \over 12 p q} = {q + 4 p \over 2 p q}\)

\(4 + {5 \over 6 x} = {4 \over 1} + {5 \over 6 x} = {24 x \over 6 x} + {5 \over 6 x} = {24 x + 5 \over 6 x}\)

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

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

\({a \over 5 a} = {1 \over 5}\)

\({6 x \over -27 x} = -\frac{2}{9}\)

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

\({12 p q \over -20 p r} = -{3 q \over 5 r}\)

\({-15 y \over -20 x y} = {3 \over 4 x}\)

\({-6 a b c \over 3 b c} = -2 a\)

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

\(7 p + {8 \over 9 p} = {7 p \over 1} ⋅ {9 p \over 9 p} + {8 \over 9 p} = {63 p^{2} \over 9 p} + {8 \over 9 p} = {63 p^{2} + 8 \over 9 p}\)

\({6 y \over 4 x} + {2 x \over 3 y} = {18 y^{2} \over 12 x y} + {8 x^{2} \over 12 x y} = {8 x^{2} + 18 y^{2} \over 12 x y} = {4 x^{2} + 9 y^{2} \over 6 x y}\)

\({3 \over a} ⋅ {4 \over b} = {12 \over a b}\)

\({a \over 9} ⋅ {4 \over b} = {4 a \over 9 b}\)

\({6 \over 5} ⋅ x = {6 x \over 5}\)

\({2 y \over x} ⋅ {x - 8 \over 6} = {2 y (x - 8) \over 6 x} = {y (x - 8) \over 3 x} = {x y - 8 y \over 3 x}\)

\({5 \over p} : {7 \over q} = {5 \over p} ⋅ {q \over 7} = {5 q \over 7 p}\)

\(-{6 \over 5} : x = -{6 \over 5} : {x \over 1} = -{6 \over 5} ⋅ {1 \over x} = -{6 \over 5 x}\)

\(-{8 \over 3} : {a + 9 b \over b} = -{8 \over 3} ⋅ {b \over a + 9 b} = -{8 b \over 3 (a + 9 b)} = -{8 b \over 3 a + 27 b}\)

\({a \over 5} + {a - 6 \over 9} = {9 a \over 45} + {5 (a - 6) \over 45} = {9 a + 5 (a - 6) \over 45} = {14 a - 30 \over 45}\)

\({6 a + 3 \over -4 a - 1} + 2 = {6 a + 3 \over -4 a - 1} - {-2 (-4 a - 1) \over -4 a - 1} = {6 a + 3 + 2 (-4 a - 1) \over -4 a - 1} = {6 a + 3 - 8 a - 2 \over -4 a - 1} = {-2 a + 1 \over -4 a - 1}\)