\({5 \over 4a}-{9 \over 4a}=-{4 \over 4a}=-{1 \over a}\)

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

\({6 \over 5p}+{9 \over 8q}={48q \over 40pq}+{45p \over 40pq}={48q+45p \over 40pq}\)

\(4-{3 \over 7x}={4 \over 1}-{3 \over 7x}={28x \over 7x}-{3 \over 7x}={28x-3 \over 7x}\)

\(4x+{8 \over 5x}={4x \over 1}⋅{5x \over 5x}+{8 \over 5x}={20x^2 \over 5x}+{8 \over 5x}={20x^2+8 \over 5x}\)

\({6x \over y}-{3 \over 7y}={42x \over 7y}-{3 \over 7y}={42x-3 \over 7y}\)

\({5q \over 2p}+{4p \over 8q}={20q^2 \over 8pq}+{4p^2 \over 8pq}={4p^2+20q^2 \over 8pq}={p^2+5q^2 \over 2pq}\)

\({5a \over a}={5 \over 1}=5\)

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

\({24a \over -28a}=-\frac{6}{7}\)

\({-27a \over -3a}=9\)

\({-14xy \over -18xz}={7y \over 9z}\)

\({6q \over 16pq}={3 \over 8p}\)

\({-8xyz \over 4yz}=-2x\)

\({6ab \over b}-{7ac \over c}=6a-7a=-a\)

\({4 \over a}⋅-{9 \over b}=-{36 \over ab}\)

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

\({1 \over 2}⋅x={x \over 2}\)

\({6 \over p}:{5 \over q}={6 \over p}⋅{q \over 5}={6q \over 5p}\)

\({5 \over 7}:a={5 \over 7}:{a \over 1}={5 \over 7}⋅{1 \over a}={5 \over 7a}\)

\({9a \over 5}+{a+6 \over 7}={63a \over 35}+{5(a+6) \over 35}={63a+5(a+6) \over 35}={68a+30 \over 35}\)