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

\({5 \over x} + {7 \over 8 x} = {40 \over 8 x} + {7 \over 8 x} = {47 \over 8 x}\)

\({9 \over 5 a} + {4 \over 8 b} = {72 b \over 40 a b} + {20 a \over 40 a b} = {72 b + 20 a \over 40 a b} = {18 b + 5 a \over 10 a b}\)

\(5 + {9 \over 8 p} = {5 \over 1} + {9 \over 8 p} = {40 p \over 8 p} + {9 \over 8 p} = {40 p + 9 \over 8 p}\)

\({9 x \over y} + {2 \over 6 y} = {54 x \over 6 y} + {2 \over 6 y} = {54 x + 2 \over 6 y} = {27 x + 1 \over 3 y}\)

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

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

\({-15 a \over -40 a} = \frac{3}{8}\)

\({18 a \over -2 a} = -9\)

\({25 x y \over -35 x z} = -{5 y \over 7 z}\)

\({-6 y \over -16 x y} = {3 \over 8 x}\)

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

\({4 a b \over b} - {7 a c \over c} = 4 a - 7 a = -3 a\)

\(3 x - {8 \over 7 x} = {3 x \over 1} ⋅ {7 x \over 7 x} - {8 \over 7 x} = {21 x^{2} \over 7 x} - {8 \over 7 x} = {21 x^{2} - 8 \over 7 x}\)

\({2 b \over 8 a} + {6 a \over 5 b} = {10 b^{2} \over 40 a b} + {48 a^{2} \over 40 a b} = {48 a^{2} + 10 b^{2} \over 40 a b} = {24 a^{2} + 5 b^{2} \over 20 a b}\)

\({9 \over a} ⋅ {3 \over b} = {27 \over a b}\)

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

\({9 \over 4} ⋅ p = {9 p \over 4}\)

\({8 b \over a} ⋅ {a + 2 \over 7} = {8 b (a + 2) \over 7 a} = {8 a b + 16 b \over 7 a}\)

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

\({5 \over 8} : a = {5 \over 8} : {a \over 1} = {5 \over 8} ⋅ {1 \over a} = {5 \over 8 a}\)

\(-{8 \over 3} : {p - 5 q \over q} = -{8 \over 3} ⋅ {q \over p - 5 q} = -{8 q \over 3 (p - 5 q)} = -{8 q \over 3 p - 15 q}\)

\({x \over 4} + {x + 7 \over 9} = {9 x \over 36} + {4 (x + 7) \over 36} = {9 x + 4 (x + 7) \over 36} = {13 x + 28 \over 36}\)

\({-4 a - 2 \over 7 a - 3} + 6 = {-4 a - 2 \over 7 a - 3} + {6 (7 a - 3) \over 7 a - 3} = {-4 a - 2 + 6 (7 a - 3) \over 7 a - 3} = {-4 a - 2 + 42 a - 18 \over 7 a - 3} = {38 a - 20 \over 7 a - 3}\)

\({9 p^{2} + p + 7 \over 6 p^{2}} = {9 p^{2} \over 6 p^{2}} + {p \over 6 p^{2}} + {7 \over 6 p^{2}} = 1\frac{1}{2} + {1 \over 6 p} + {7 \over 6 p^{2}}\)