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

\({4 \over p}-{3 \over 7p}={28 \over 7p}-{3 \over 7p}={25 \over 7p}\)

\({2 \over 3x}-{9 \over 8y}={16y \over 24xy}-{27x \over 24xy}={16y-27x \over 24xy}\)

\(5+{3 \over 4a}={5 \over 1}+{3 \over 4a}={20a \over 4a}+{3 \over 4a}={20a+3 \over 4a}\)

\({8x \over y}-{5 \over 2y}={16x \over 2y}-{5 \over 2y}={16x-5 \over 2y}\)

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

\({a \over 6a}={1 \over 6}\)

\({14x \over -16x}=-\frac{7}{8}\)

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

\({40pq \over -45pr}=-{8q \over 9r}\)

\({10q \over -45pq}=-{2 \over 9p}\)

\({-15abc \over 5bc}=-3a\)

\({4xy \over y}+{2xz \over z}=4x+2x=6x\)