Question

simplify (4m+5n)^2 - (5m+4n)^2​

Answer 1

The answer of the question is-9m2+9n2

Answer 2

${(4m + 5n)}^{2} - {( 5m+ 4n)}^{2} \\ \\ ( {16m}^{2} + {25n}^{2} + 40mn ) - ( {25m}^{2} + {16n}^{2} + 40mn) \\ {16m}^{2} + {25n}^{2} + 40mn - {25m}^{2} - {16n}^{2} - 40mn \\ {16m}^{2} + {25n}^{2} - {25m}^{2} - {16n}^{2} \\ {9n}^{2} - {9m}^{2} \\ (3n - 3m)(3n + 3m)$