\({8 \over 9 a} + {7 \over 9 a} = {15 \over 9 a} = {5 \over 3 a}\)

\({4 \over x} + {5 \over 3 x} = {12 \over 3 x} + {5 \over 3 x} = {17 \over 3 x}\)

\({3 \over 9 x} - {8 \over 2 y} = {6 y \over 18 x y} - {72 x \over 18 x y} = {6 y - 72 x \over 18 x y} = {y - 12 x \over 3 x y}\)

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

\({4 p \over q} - {3 \over 9 q} = {36 p \over 9 q} - {3 \over 9 q} = {36 p - 3 \over 9 q} = {12 p - 1 \over 3 q}\)

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

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

\({32 x \over 36 x} = \frac{8}{9}\)

\({-10 a \over -5 a} = 2\)

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

\({15 b \over -27 a b} = -{5 \over 9 a}\)

\({25 p q r \over 5 q r} = 5 p\)

\({5 x y \over y} + {4 x z \over z} = 5 x + 4 x = 9 x\)

\(9 x + {6 \over 5 x} = {9 x \over 1} ⋅ {5 x \over 5 x} + {6 \over 5 x} = {45 x^{2} \over 5 x} + {6 \over 5 x} = {45 x^{2} + 6 \over 5 x}\)

\({4 y \over 7 x} + {6 x \over 5 y} = {20 y^{2} \over 35 x y} + {42 x^{2} \over 35 x y} = {42 x^{2} + 20 y^{2} \over 35 x y}\)

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

\({p \over 8} ⋅ {2 \over q} = {2 p \over 8 q} = {p \over 4 q}\)

\({1 \over 4} ⋅ a = {a \over 4}\)

\({3 y \over x} ⋅ {x - 5 \over 2} = {3 y (x - 5) \over 2 x} = {3 x y - 15 y \over 2 x}\)

\({6 \over p} : {3 \over q} = {6 \over p} ⋅ {q \over 3} = {6 q \over 3 p} = {2 q \over p}\)

\(-{3 \over 4} : x = -{3 \over 4} : {x \over 1} = -{3 \over 4} ⋅ {1 \over x} = -{3 \over 4 x}\)

\({9 \over 5} : {a - 7 b \over b} = {9 \over 5} ⋅ {b \over a - 7 b} = {9 b \over 5 (a - 7 b)} = {9 b \over 5 a - 35 b}\)

\({5 a \over 4} + {a + 3 \over 7} = {35 a \over 28} + {4 (a + 3) \over 28} = {35 a + 4 (a + 3) \over 28} = {39 a + 12 \over 28}\)