\({8 \over 7 a} + {9 \over 7 a} = {17 \over 7 a}\)

\({4 \over x} + {5 \over 9 x} = {36 \over 9 x} + {5 \over 9 x} = {41 \over 9 x}\)

\({2 \over 8 p} - {5 \over 7 q} = {14 q \over 56 p q} - {40 p \over 56 p q} = {14 q - 40 p \over 56 p q} = {7 q - 20 p \over 28 p q}\)

\(7 - {8 \over 9 a} = {7 \over 1} - {8 \over 9 a} = {63 a \over 9 a} - {8 \over 9 a} = {63 a - 8 \over 9 a}\)

\(6 x - {5 \over 2 x} = {6 x \over 1} ⋅ {2 x \over 2 x} - {5 \over 2 x} = {12 x^{2} \over 2 x} - {5 \over 2 x} = {12 x^{2} - 5 \over 2 x}\)

\({8 x \over y} - {7 \over 5 y} = {40 x \over 5 y} - {7 \over 5 y} = {40 x - 7 \over 5 y}\)

\({9 y \over 3 x} - {2 x \over 8 y} = {72 y^{2} \over 24 x y} - {6 x^{2} \over 24 x y} = {-6 x^{2} + 72 y^{2} \over 24 x y} = {-x^{2} + 12 y^{2} \over 4 x y}\)

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

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

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

\({12 a \over 2 a} = 6\)

\({12 p q \over -16 p r} = -{3 q \over 4 r}\)

\({25 y \over -45 x y} = -{5 \over 9 x}\)

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

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

\({9 \over a} ⋅ -{7 \over b} = -{63 \over a b}\)

\({x \over 9} ⋅ -{8 \over y} = -{8 x \over 9 y}\)

\(-{5 \over 6} ⋅ a = -{5 a \over 6}\)

\({9 \over x} : {5 \over y} = {9 \over x} ⋅ {y \over 5} = {9 y \over 5 x}\)

\(-{8 \over 3} : p = -{8 \over 3} : {p \over 1} = -{8 \over 3} ⋅ {1 \over p} = -{8 \over 3 p}\)

\({8 p \over 9} + {p + 6 \over 4} = {32 p \over 36} + {9 (p + 6) \over 36} = {32 p + 9 (p + 6) \over 36} = {41 p + 54 \over 36}\)

\({9 y \over x} ⋅ {x + 7 \over 8} = {9 y (x + 7) \over 8 x} = {9 x y + 63 y \over 8 x}\)

\({2 \over 9} : {p - 4 q \over q} = {2 \over 9} ⋅ {q \over p - 4 q} = {2 q \over 9 (p - 4 q)} = {2 q \over 9 p - 36 q}\)

\({6 x^{2} + 2 x + 40 \over 2 x} = {6 x^{2} \over 2 x} + {2 x \over 2 x} + {40 \over 2 x} = 3 x + 1 + {20 \over x}\)

\({3 a^{2} + a + 6 \over 8 a^{2}} = {3 a^{2} \over 8 a^{2}} + {a \over 8 a^{2}} + {6 \over 8 a^{2}} = \frac{3}{8} + {1 \over 8 a} + {3 \over 4 a^{2}}\)