Question

help me in the 5th one​

Answer 1

18x+98y



Is the answer((:

Answer 2

Step-by-step explanation:

$given \: it \: \\ 3x - 7y = 10 \: \: xy = - 1 \\ \\ 9 {x}^{2} + 49 {y}^{2} = {(3x)}^{2} + {(7y)}^{2} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = {(3x - 7y)}^{2} + 42xy \\ using \: the \: formula \: \: {a}^{2} + {b}^{2} = {(a - b)}^{2} + 2ab \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = {10}^{2} + 42 \times - 1 \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 100 - 42 = 58 \\ \\ hope \: it \: will \: help \: you...$