Question

simplify by useing suitable indentities​

Answer 1

Answer:

${(4m + 5n)}^{2} + {(5m + 4n)}^{2} \\ = {(4m)}^{2} + {(5n)}^{2} + 2(4m)(5n) + {(5m)}^{2} + {(4n)}^{2} + 2(5m)(4n) \\ = 16 {m}^{2} + 25 {n}^{2} + 40mn + 25 {m}^{2} + 16 {n}^{2} + 40mn \\ = 41 {m}^{2} + 41 {n}^{2} + 80mn$