\({4 \over 8 x} - {9 \over 8 x} = -{5 \over 8 x}\)

\({6 \over a} + {9 \over 5 a} = {30 \over 5 a} + {9 \over 5 a} = {39 \over 5 a}\)

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

\(8 + {5 \over 9 p} = {8 \over 1} + {5 \over 9 p} = {72 p \over 9 p} + {5 \over 9 p} = {72 p + 5 \over 9 p}\)

\(2 x - {7 \over 4 x} = {2 x \over 1} ⋅ {4 x \over 4 x} - {7 \over 4 x} = {8 x^{2} \over 4 x} - {7 \over 4 x} = {8 x^{2} - 7 \over 4 x}\)

\({5 a \over b} + {7 \over 8 b} = {40 a \over 8 b} + {7 \over 8 b} = {40 a + 7 \over 8 b}\)

\({9 y \over 5 x} + {7 x \over 8 y} = {72 y^{2} \over 40 x y} + {35 x^{2} \over 40 x y} = {35 x^{2} + 72 y^{2} \over 40 x y}\)

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

\({a \over 8 a} = {1 \over 8}\)

\({10 x \over -35 x} = -\frac{2}{7}\)

\({-14 a \over 2 a} = -7\)

\({-6 p q \over -21 p r} = {2 q \over 7 r}\)

\({20 y \over 28 x y} = {5 \over 7 x}\)

\({-40 a b c \over 5 b c} = -8 a\)

\({2 x y \over y} + {4 x z \over z} = 2 x + 4 x = 6 x\)

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

\({x \over 8} ⋅ -{2 \over y} = -{2 x \over 8 y} = -{x \over 4 y}\)

\({1 \over 2} ⋅ a = {a \over 2}\)

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

\(-{4 \over 5} : p = -{4 \over 5} : {p \over 1} = -{4 \over 5} ⋅ {1 \over p} = -{4 \over 5 p}\)

\({8 p \over 3} + {p - 1 \over 7} = {56 p \over 21} + {3 (p - 1) \over 21} = {56 p + 3 (p - 1) \over 21} = {59 p - 3 \over 21}\)

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

\({6 \over 5} : {a + 8 b \over b} = {6 \over 5} ⋅ {b \over a + 8 b} = {6 b \over 5 (a + 8 b)} = {6 b \over 5 a + 40 b}\)

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

\({5 a^{2} + 4 a - 6 \over 3 a^{2}} = {5 a^{2} \over 3 a^{2}} + {4 a \over 3 a^{2}} - {6 \over 3 a^{2}} = 1\frac{2}{3} + {4 \over 3 a} - {2 \over a^{2}}\)