\({7 \over 9p}-{2 \over 9p}={5 \over 9p}\)

\({4 \over x}-{7 \over 8x}={32 \over 8x}-{7 \over 8x}={25 \over 8x}\)

\({5 \over 9a}-{7 \over 2b}={10b \over 18ab}-{63a \over 18ab}={10b-63a \over 18ab}\)

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

\(5a-{3 \over 8a}={5a \over 1}⋅{8a \over 8a}-{3 \over 8a}={40a^2 \over 8a}-{3 \over 8a}={40a^2-3 \over 8a}\)

\({2x \over y}+{9 \over 4y}={8x \over 4y}+{9 \over 4y}={8x+9 \over 4y}\)

\({5q \over 2p}-{9p \over 6q}={15q^2 \over 6pq}-{9p^2 \over 6pq}={-9p^2+15q^2 \over 6pq}={-3p^2+5q^2 \over 2pq}\)

\({4a \over a}={4 \over 1}=4\)

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

\({10a \over 35a}=\frac{2}{7}\)

\({-14x \over 2x}=-7\)

\({-20pq \over -28pr}={5q \over 7r}\)

\({20b \over 36ab}={5 \over 9a}\)

\({-21xyz \over 3yz}=-7x\)

\({4ab \over b}+{7ac \over c}=4a+7a=11a\)

\({3 \over a}⋅{9 \over b}={27 \over ab}\)

\({p \over 9}⋅{4 \over q}={4p \over 9q}\)

\(-{8 \over 7}⋅x=-{8x \over 7}\)

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

\(-{4 \over 5}:x=-{4 \over 5}:{x \over 1}=-{4 \over 5}⋅{1 \over x}=-{4 \over 5x}\)

\({7x \over 4}+{x-1 \over 9}={63x \over 36}+{4(x-1) \over 36}={63x+4(x-1) \over 36}={67x-4 \over 36}\)

\(-{2 \over 7}:{x-y \over y}=-{2 \over 7}⋅{y \over x-y}=-{2y \over 7(x-y)}=-{2y \over 7x-7y}\)

\({5a+9 \over -3a-7}+6={5a+9 \over -3a-7}-{-6(-3a-7) \over -3a-7}={5a+9+6(-3a-7) \over -3a-7}={5a+9-18a-42 \over -3a-7}={-13a-33 \over -3a-7}\)