\({3 \over 8x}-{5 \over 8x}=-{2 \over 8x}=-{1 \over 4x}\)

\({7 \over a}-{4 \over 2a}={14 \over 2a}-{4 \over 2a}={10 \over 2a}={5 \over a}\)

\({9 \over 2a}+{5 \over 7b}={63b \over 14ab}+{10a \over 14ab}={63b+10a \over 14ab}\)

\(4+{8 \over 9x}={4 \over 1}+{8 \over 9x}={36x \over 9x}+{8 \over 9x}={36x+8 \over 9x}\)

\({9p \over q}+{5 \over 4q}={36p \over 4q}+{5 \over 4q}={36p+5 \over 4q}\)

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

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

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

\({-20x \over 4x}=-5\)

\({6pq \over 14pr}={3q \over 7r}\)

\({6y \over 8xy}={3 \over 4x}\)

\({-18xyz \over 3yz}=-6x\)

\({4pq \over q}-{6pr \over r}=4p-6p=-2p\)

\(6a+{3 \over 5a}={6a \over 1}⋅{5a \over 5a}+{3 \over 5a}={30a^2 \over 5a}+{3 \over 5a}={30a^2+3 \over 5a}\)

\({2b \over 8a}+{9a \over 4b}={2b^2 \over 8ab}+{18a^2 \over 8ab}={18a^2+2b^2 \over 8ab}={9a^2+b^2 \over 4ab}\)

\({5 \over p}⋅-{6 \over q}=-{30 \over pq}\)

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

\(-{8 \over 3}⋅x=-{8x \over 3}\)

\({7y \over x}⋅{x+2 \over 5}={7y(x+2) \over 5x}={7xy+14y \over 5x}\)

\({9 \over x}:{7 \over y}={9 \over x}⋅{y \over 7}={9y \over 7x}\)

\({2 \over 5}:p={2 \over 5}:{p \over 1}={2 \over 5}⋅{1 \over p}={2 \over 5p}\)

\(-{3 \over 4}:{a-2b \over b}=-{3 \over 4}⋅{b \over a-2b}=-{3b \over 4(a-2b)}=-{3b \over 4a-8b}\)

\({9a \over 4}+{a-2 \over 7}={63a \over 28}+{4(a-2) \over 28}={63a+4(a-2) \over 28}={67a-8 \over 28}\)