\({6 \over 7 a} + {8 \over 7 a} = {14 \over 7 a} = {2 \over a}\)

\({3 \over x} + {9 \over 4 x} = {12 \over 4 x} + {9 \over 4 x} = {21 \over 4 x}\)

\({4 \over 5 x} - {8 \over 7 y} = {28 y \over 35 x y} - {40 x \over 35 x y} = {28 y - 40 x \over 35 x y}\)

\(5 - {2 \over 7 p} = {5 \over 1} - {2 \over 7 p} = {35 p \over 7 p} - {2 \over 7 p} = {35 p - 2 \over 7 p}\)

\(3 a + {7 \over 4 a} = {3 a \over 1} ⋅ {4 a \over 4 a} + {7 \over 4 a} = {12 a^{2} \over 4 a} + {7 \over 4 a} = {12 a^{2} + 7 \over 4 a}\)

\({2 a \over b} - {5 \over 9 b} = {18 a \over 9 b} - {5 \over 9 b} = {18 a - 5 \over 9 b}\)

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

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

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

\({10 p \over -16 p} = -\frac{5}{8}\)

\({32 a \over -4 a} = -8\)

\({20 p q \over 36 p r} = {5 q \over 9 r}\)

\({8 y \over 36 x y} = {2 \over 9 x}\)

\({15 a b c \over -3 b c} = -5 a\)

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

\({6 \over a} ⋅ {5 \over b} = {30 \over a b}\)

\({x \over 9} ⋅ -{6 \over y} = -{6 x \over 9 y} = -{2 x \over 3 y}\)

\({7 \over 2} ⋅ p = {7 p \over 2}\)

\({2 \over a} : {8 \over b} = {2 \over a} ⋅ {b \over 8} = {2 b \over 8 a} = {b \over 4 a}\)

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