Which of these strategies would eliminate a variable in the system of equations?{−7x+2y=53x−5y=−5Choose 2 answers:(A) Multiply the top equation by 3 , multiply the bottom equation by 7 , then add the equations.(B) Add the equations.(C) Multiply the top equation by 5 , multiply the bottom equation by 2 , then add the equations.
Q. Which of these strategies would eliminate a variable in the system of equations?{−7x+2y=53x−5y=−5Choose 2 answers:(A) Multiply the top equation by 3 , multiply the bottom equation by 7 , then add the equations.(B) Add the equations.(C) Multiply the top equation by 5 , multiply the bottom equation by 2 , then add the equations.
Analyze system of equations: Analyze the given system of equations to determine which variable can be eliminated using the given strategies.The system of equations is:−7x+2y=53x−5y=−5
Strategy A: Multiply and add equations: Consider strategy A: Multiply the top equation by 3, multiply the bottom equation by 7, then add the equations.Multiplying the top equation by 3 gives us:−21x+6y=15Multiplying the bottom equation by 7 gives us:21x−35y=−35
Check elimination of variable : Add the equations from strategy A to see if a variable is eliminated.\newlineThe x terms cancel out, and we are left with:\newline666y - 353535y = −20-20−20\newline−29-29−29y = −20-20−20\newlineThis strategy eliminates the variable x.
Strategy B: Add equations: Consider strategy B: Add the equations without any multiplication.\newline(−7x+2y)+(3x−5y)=5−5(-7x + 2y) + (3x - 5y) = 5 - 5(−7x+2y)+(3x−5y)=5−5\newline−7x+3x+2y−5y=0-7x + 3x + 2y - 5y = 0−7x+3x+2y−5y=0\newline−4x−3y=0-4x - 3y = 0−4x−3y=0\newlineThis strategy does not eliminate any variable, as both xxx and yyy are still present in the equation.
No elimination of variables: Consider strategy C: Multiply the top equation by 555, multiply the bottom equation by 222, then add the equations.\newlineMultiplying the top equation by 555 gives us:\newline−35x+10y=25-35x + 10y = 25−35x+10y=25\newlineMultiplying the bottom equation by 222 gives us:\newline6x−10y=−106x - 10y = -106x−10y=−10
Strategy C: Multiply and add equations: Add the equations from strategy C to see if a variable is eliminated.\newline(−35x+10y)+(6x−10y)=25−10(-35x + 10y) + (6x - 10y) = 25 - 10(−35x+10y)+(6x−10y)=25−10\newlineThe y terms cancel out, and we are left with:\newline−35x+6x=15-35x + 6x = 15−35x+6x=15\newline−29x=15-29x = 15−29x=15\newlineThis strategy eliminates the variable y.
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