\({2 \over 5 a} + {7 \over 5 a} = {9 \over 5 a}\)

\({5 \over p} - {3 \over 2 p} = {10 \over 2 p} - {3 \over 2 p} = {7 \over 2 p}\)

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

\(7 - {4 \over 5 x} = {7 \over 1} - {4 \over 5 x} = {35 x \over 5 x} - {4 \over 5 x} = {35 x - 4 \over 5 x}\)

\({7 a \over b} - {3 \over 2 b} = {14 a \over 2 b} - {3 \over 2 b} = {14 a - 3 \over 2 b}\)

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

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

\({8 a \over -12 a} = -\frac{2}{3}\)

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

\({-40 x y \over 45 x z} = -{8 y \over 9 z}\)

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

\({21 a b c \over -3 b c} = -7 a\)

\({5 p q \over q} + {3 p r \over r} = 5 p + 3 p = 8 p\)

\(9 p + {5 \over 6 p} = {9 p \over 1} ⋅ {6 p \over 6 p} + {5 \over 6 p} = {54 p^{2} \over 6 p} + {5 \over 6 p} = {54 p^{2} + 5 \over 6 p}\)

\({8 y \over 4 x} - {2 x \over 5 y} = {40 y^{2} \over 20 x y} - {8 x^{2} \over 20 x y} = {-8 x^{2} + 40 y^{2} \over 20 x y} = {-2 x^{2} + 10 y^{2} \over 5 x y}\)

\({5 \over x} ⋅ {2 \over y} = {10 \over x y}\)

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

\({2 \over 7} ⋅ a = {2 a \over 7}\)

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

\({6 \over x} : {7 \over y} = {6 \over x} ⋅ {y \over 7} = {6 y \over 7 x}\)

\({8 \over 9} : p = {8 \over 9} : {p \over 1} = {8 \over 9} ⋅ {1 \over p} = {8 \over 9 p}\)

\({7 \over 9} : {x - 6 y \over y} = {7 \over 9} ⋅ {y \over x - 6 y} = {7 y \over 9 (x - 6 y)} = {7 y \over 9 x - 54 y}\)

\({a \over 2} + {a + 6 \over 3} = {3 a \over 6} + {2 (a + 6) \over 6} = {3 a + 2 (a + 6) \over 6} = {5 a + 12 \over 6}\)

\({4 p + 6 \over -3 p + 9} - 7 = {4 p + 6 \over -3 p + 9} + {-7 (-3 p + 9) \over -3 p + 9} = {4 p + 6 - 7 (-3 p + 9) \over -3 p + 9} = {4 p + 6 + 21 p - 63 \over -3 p + 9} = {25 p - 57 \over -3 p + 9}\)

\({6 x^{2} + 9 x + 30 \over 3 x} = {6 x^{2} \over 3 x} + {9 x \over 3 x} + {30 \over 3 x} = 2 x + 3 + {10 \over x}\)

\({8 a^{2} - 4 a - 9 \over 2 a^{2}} = {8 a^{2} \over 2 a^{2}} - {4 a \over 2 a^{2}} - {9 \over 2 a^{2}} = 4 - {2 \over a} - {9 \over 2 a^{2}}\)