\({2 \over 5 a} - {7 \over 5 a} = -{5 \over 5 a} = -{1 \over a}\)

\({8 \over p} - {4 \over 9 p} = {72 \over 9 p} - {4 \over 9 p} = {68 \over 9 p}\)

\({4 \over 8 x} + {2 \over 6 y} = {12 y \over 24 x y} + {8 x \over 24 x y} = {12 y + 8 x \over 24 x y} = {3 y + 2 x \over 6 x y}\)

\(6 + {4 \over 7 a} = {6 \over 1} + {4 \over 7 a} = {42 a \over 7 a} + {4 \over 7 a} = {42 a + 4 \over 7 a}\)

\({9 x \over y} - {8 \over 7 y} = {63 x \over 7 y} - {8 \over 7 y} = {63 x - 8 \over 7 y}\)

\({9 a \over a} = {9 \over 1} = 9\)

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

\({18 x \over 21 x} = \frac{6}{7}\)

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

\({20 p q \over 32 p r} = {5 q \over 8 r}\)

\({18 y \over -21 x y} = -{6 \over 7 x}\)

\({-24 a b c \over 3 b c} = -8 a\)

\({7 x y \over y} + {2 x z \over z} = 7 x + 2 x = 9 x\)

\(2 a + {3 \over 4 a} = {2 a \over 1} ⋅ {4 a \over 4 a} + {3 \over 4 a} = {8 a^{2} \over 4 a} + {3 \over 4 a} = {8 a^{2} + 3 \over 4 a}\)

\({4 y \over 3 x} - {9 x \over 5 y} = {20 y^{2} \over 15 x y} - {27 x^{2} \over 15 x y} = {-27 x^{2} + 20 y^{2} \over 15 x y}\)

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

\({p \over 8} ⋅ {3 \over q} = {3 p \over 8 q}\)

\(-{6 \over 5} ⋅ x = -{6 x \over 5}\)

\({6 q \over p} ⋅ {p + 5 \over 9} = {6 q (p + 5) \over 9 p} = {2 q (p + 5) \over 3 p} = {2 p q + 10 q \over 3 p}\)

\({8 \over x} : {7 \over y} = {8 \over x} ⋅ {y \over 7} = {8 y \over 7 x}\)

\({5 \over 3} : a = {5 \over 3} : {a \over 1} = {5 \over 3} ⋅ {1 \over a} = {5 \over 3 a}\)

\(-{9 \over 5} : {a - 8 b \over b} = -{9 \over 5} ⋅ {b \over a - 8 b} = -{9 b \over 5 (a - 8 b)} = -{9 b \over 5 a - 40 b}\)

\({x \over 9} + {x + 6 \over 8} = {8 x \over 72} + {9 (x + 6) \over 72} = {8 x + 9 (x + 6) \over 72} = {17 x + 54 \over 72}\)

\({6 a + 1 \over -3 a - 5} + 2 = {6 a + 1 \over -3 a - 5} - {-2 (-3 a - 5) \over -3 a - 5} = {6 a + 1 + 2 (-3 a - 5) \over -3 a - 5} = {6 a + 1 - 6 a - 10 \over -3 a - 5} = {-9 \over -3 a - 5}\)

\({p^{2} - 3 p + 20 \over p} = {p^{2} \over p} - {3 p \over p} + {20 \over p} = p - 3 + {20 \over p}\)

\({8 a^{2} - 2 a + 7 \over 9 a^{2}} = {8 a^{2} \over 9 a^{2}} - {2 a \over 9 a^{2}} + {7 \over 9 a^{2}} = \frac{8}{9} - {2 \over 9 a} + {7 \over 9 a^{2}}\)