Which of these strategies would eliminate a variable in the system of equations? \begin{cases} 6x + 5y = 1 6x - 5y = 7 \end{cases} ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ 6x+5y=1 6x−5y=7 Choose all answers that apply: Choose all answers that apply: (Choice A) A Add the equations. (Choice B) B Subtract the bottom equation from the top equation. (Choice C) C Multiply the top equation by 777, then subtract the bottom equation from the top equation.