Question

Tell the answer of Q1 3rd part​

Answer 1

$( \frac{2a}{5b} - \frac{5b}{2a} ) ^{2} \: \: is \: basically \: (a - b) ^{2}$

${(a - b)}^{2} = {a}^{2} - 2ab + {b}^{2}$

$( \frac{2a}{5b} - \frac{5b}{2a} ) ^{2} = ( \: (\frac{2a}{5b} ) ^{2} - 2( \frac{2a}{5b} \times \frac{5b}{2a} ) +( \frac{5b}{2a} ) ^{2}$

$= \frac{4 {a}^{2} }{25b ^{2} } - 2( \frac{10ab}{10ab}) + \frac{25b ^{2} }{4a^{2} }$

$= \frac{4 {a}^{2} }{25 {b}^{2} } + \frac{25 {b}^{2} }{4 {a}^{2} } - 2$