Which of these strategies would eliminate a variable in the system of equations?{−x+6y=87x−y=−2Choose 1 answers:(A) Add the equations.(B) Multiply the bottom equation by 6 , then subtract the bottom equation from the top equation.(C) Multiply the top equation by 7 , then add the equations.
Q. Which of these strategies would eliminate a variable in the system of equations?{−x+6y=87x−y=−2Choose 1 answers:(A) Add the equations.(B) Multiply the bottom equation by 6 , then subtract the bottom equation from the top equation.(C) Multiply the top equation by 7 , then add the equations.
Analyze the system: Analyze the given system of equations to determine which strategy would eliminate a variable.The system of equations is:−x+6y=87x−y=−2We need to find a strategy that will eliminate either ′x′ or ′y′ when we combine the two equations.
Evaluate option A: Evaluate option A: Add the equations.If we add the equations directly, we get:(−x+6y)+(7x−y)=8+(−2)This simplifies to:6x+5y=6This does not eliminate any variable.
Evaluate option B: Evaluate option B: Multiply the bottom equation by 6, then subtract the bottom equation from the top equation.First, we multiply the bottom equation by 6:6×(7x−y)=6×(−2)This gives us:42x−6y=−12Now, we subtract this new equation from the top equation:(−x+6y)−(42x−6y)=8−(−12)This simplifies to:−x+6y−42x+6y=8+12Combining like terms, we get:−43x+12y=20This does not eliminate any variable.
Evaluate option C: Evaluate option C: Multiply the top equation by 7, then add the equations.First, we multiply the top equation by 7:7⋅(−x+6y)=7⋅8This gives us:−7x+42y=56Now, we add this new equation to the bottom equation:(−7x+42y)+(7x−y)=56+(−2)This simplifies to:−7x+42y+7x−y=54Combining like terms, we get:41y=54This eliminates the variable 'x'.
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