Question

please give step by step explanation
don't give spam ans​

Answer 1

I hope it is useful to you .

Answer 2

Step-by-step explanation:

As the given equation is,

$3 {x}^{2} - 4 {y}^{2} + 5xy + 20$

The final equation required is,

$- {x}^{2} - {y}^{2} + 6xy + 20$

Thus, the equation taken away from the given equation to obtain the final equation is,

$3 {x}^{2} - 4 {y}^{2} + 5xy + 20 - ( - {x}^{2} - {y}^{2} + 6xy + 20) \\3 {x}^{2} - 4 {y}^{2} + 5xy + 20 + {x}^{2} + {y}^{2} - 6xy - 20) \\ {x}^{2}(3 + 1) + {y}^{2} ( - 4 + 1) + xy(5 - 6) \\ 4 {x}^{2} - 3 {y}^{2} - xy$

Hence, option A is the correct answer.