[tex] \frac{7d}{b} - \frac{5d}{b} = \frac{2d}{b} [/tex]

[tex] \frac{2x + y}{4} - \frac{5y + 2x}{4} = \frac{2x + y - 5y - 2x}{4} = \frac{ - 4y}{4} = - y \\ \frac{m + 2}{4m} + \frac{7 - 5t}{20t} = \frac{5t(m + 2) + m(7 - 5t)}{20tm} = \frac{5tm + 10t + 7m - 5tm}{20tm} = \frac{10t + 7m}{20tm} [/tex]

[tex] \frac{15}{ {s}^{2} + 3s} - \frac{5}{s} = \frac{15}{s(s + 3)} - \frac{5}{s} = \frac{15 - 5(s + 3)}{s(s + 3)} = \frac{15 - 5s - 15}{ {s}^{2} + 3s } = \frac{ - 5s}{s(s + 3)} = - \frac{5}{s + 3} [/tex]

[tex] \frac{ {b}^{2} + 49 {p}^{2} }{b - 7p} + \frac{14bp}{7p - b} = \frac{ {b}^{2} + 49 {p}^{2} }{b - 7p} - \frac{14bp}{b - 7p} = \frac{ {b}^{2} - 14bp + 49 {p}^{2} }{b - 7p} = \frac{ {(b - 7p)}^{2} }{b - 7p} = b - 7p[/tex]