4-2a-b-2-a-b-2-

Question Number 27761 by shiv15031973@gmail.com last updated on 14/Jan/18

4 {(2 a + b)}^{2} - {(a - b)}^{2}

Answered by Rasheed.Sindhi last updated on 14/Jan/18

4 {(2 a + b)}^{2} - {(a - b)}^{2}

= 4 ({4 a}^{2} + 4 ab + b^{2}) - (a^{2} - 2 ab + b^{2})

= {16 a}^{2} + 16 ab + {4 b}^{2} - a^{2} + 2 ab - b^{2}

= {15 a}^{2} + 17 ab + {3 b}^{2}