Question

Show That(9m-5n)²+180mn=81m²+90mn+25n²​

Answer 1

Step-by-step explanation:

using formula,

(a+b)² = a² + 2ab + b²

$L.H.S = (9m-5n)²+180mn \\ = {(9m)}^{2} - 2(9m)(5n) + {(5n)}^{2} + 180mn \\ = 81 {m}^{2} - 90mn + 25 {n}^{2} + 180mn \\ = 81 {m}^{2} + 180mn - 90mn + 25 {n}^{2} \\ = = 81 {m}^{2} + 90mn + 25 {n}^{2}$