\({4 \over 7 x} - {9 \over 7 x} = -{5 \over 7 x}\)

\({8 \over a} + {6 \over 5 a} = {40 \over 5 a} + {6 \over 5 a} = {46 \over 5 a}\)

\({7 \over 9 p} + {3 \over 8 q} = {56 q \over 72 p q} + {27 p \over 72 p q} = {56 q + 27 p \over 72 p q}\)

\(9 - {3 \over 4 a} = {9 \over 1} - {3 \over 4 a} = {36 a \over 4 a} - {3 \over 4 a} = {36 a - 3 \over 4 a}\)

\({3 x \over y} - {2 \over 8 y} = {24 x \over 8 y} - {2 \over 8 y} = {24 x - 2 \over 8 y} = {12 x - 1 \over 4 y}\)

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

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

\({-14 p \over 18 p} = -\frac{7}{9}\)

\({-45 a \over -5 a} = 9\)

\({-10 x y \over -12 x z} = {5 y \over 6 z}\)

\({-16 b \over 36 a b} = -{4 \over 9 a}\)

\({16 x y z \over -4 y z} = -4 x\)

\({3 x y \over y} + {7 x z \over z} = 3 x + 7 x = 10 x\)

\(7 p + {9 \over 2 p} = {7 p \over 1} ⋅ {2 p \over 2 p} + {9 \over 2 p} = {14 p^{2} \over 2 p} + {9 \over 2 p} = {14 p^{2} + 9 \over 2 p}\)

\({6 y \over 2 x} + {7 x \over 3 y} = {18 y^{2} \over 6 x y} + {14 x^{2} \over 6 x y} = {14 x^{2} + 18 y^{2} \over 6 x y} = {7 x^{2} + 9 y^{2} \over 3 x y}\)

\({7 \over x} ⋅ -{4 \over y} = -{28 \over x y}\)

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

\(-{1 \over 6} ⋅ a = -{a \over 6}\)

\({9 b \over a} ⋅ {a - 5 \over 2} = {9 b (a - 5) \over 2 a} = {9 a b - 45 b \over 2 a}\)

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

\(-{2 \over 3} : x = -{2 \over 3} : {x \over 1} = -{2 \over 3} ⋅ {1 \over x} = -{2 \over 3 x}\)

\({3 \over 4} : {p + q \over q} = {3 \over 4} ⋅ {q \over p + q} = {3 q \over 4 (p + q)} = {3 q \over 4 p + 4 q}\)

\({7 x \over 3} + {x + 9 \over 5} = {35 x \over 15} + {3 (x + 9) \over 15} = {35 x + 3 (x + 9) \over 15} = {38 x + 27 \over 15}\)