\({3 \over 2 a} + {4 \over 2 a} = {7 \over 2 a}\)

\({2 \over x} - {3 \over 8 x} = {16 \over 8 x} - {3 \over 8 x} = {13 \over 8 x}\)

\({7 \over 5 p} + {3 \over 2 q} = {14 q \over 10 p q} + {15 p \over 10 p q} = {14 q + 15 p \over 10 p q}\)

\(2 + {7 \over 5 x} = {2 \over 1} + {7 \over 5 x} = {10 x \over 5 x} + {7 \over 5 x} = {10 x + 7 \over 5 x}\)

\({7 a \over b} + {4 \over 9 b} = {63 a \over 9 b} + {4 \over 9 b} = {63 a + 4 \over 9 b}\)

\({2 x \over x} = {2 \over 1} = 2\)

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

\({-12 a \over -28 a} = \frac{3}{7}\)

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

\({4 x y \over 18 x z} = {2 y \over 9 z}\)

\({4 b \over -14 a b} = -{2 \over 7 a}\)

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

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

\(8 x - {2 \over 9 x} = {8 x \over 1} ⋅ {9 x \over 9 x} - {2 \over 9 x} = {72 x^{2} \over 9 x} - {2 \over 9 x} = {72 x^{2} - 2 \over 9 x}\)

\({3 b \over 7 a} - {6 a \over 9 b} = {27 b^{2} \over 63 a b} - {42 a^{2} \over 63 a b} = {-42 a^{2} + 27 b^{2} \over 63 a b} = {-14 a^{2} + 9 b^{2} \over 21 a b}\)

\({2 \over a} ⋅ {7 \over b} = {14 \over a b}\)

\({p \over 3} ⋅ {5 \over q} = {5 p \over 3 q}\)

\(-{9 \over 7} ⋅ x = -{9 x \over 7}\)

\({9 q \over p} ⋅ {p + 3 \over 5} = {9 q (p + 3) \over 5 p} = {9 p q + 27 q \over 5 p}\)

\({5 \over x} : {4 \over y} = {5 \over x} ⋅ {y \over 4} = {5 y \over 4 x}\)

\({1 \over 3} : a = {1 \over 3} : {a \over 1} = {1 \over 3} ⋅ {1 \over a} = {1 \over 3 a}\)

\(-{2 \over 5} : {a + b \over b} = -{2 \over 5} ⋅ {b \over a + b} = -{2 b \over 5 (a + b)} = -{2 b \over 5 a + 5 b}\)

\({x \over 3} + {x + 4 \over 2} = {2 x \over 6} + {3 (x + 4) \over 6} = {2 x + 3 (x + 4) \over 6} = {5 x + 12 \over 6}\)

\({9 x + 6 \over 3 x + 5} + 4 = {9 x + 6 \over 3 x + 5} + {4 (3 x + 5) \over 3 x + 5} = {9 x + 6 + 4 (3 x + 5) \over 3 x + 5} = {9 x + 6 + 12 x + 20 \over 3 x + 5} = {21 x + 26 \over 3 x + 5}\)

\({2 a^{2} + 4 a - 9 \over 3 a^{2}} = {2 a^{2} \over 3 a^{2}} + {4 a \over 3 a^{2}} - {9 \over 3 a^{2}} = \frac{2}{3} + {4 \over 3 a} - {3 \over a^{2}}\)