Which of these strategies would eliminate a variable in the system of equations?{x−2y=115x+3y=−11Choose 1 answers:(A) Multiply the top equation by 5 , then add the equations.(B) Add the equations.(C) Multiply the top equation by −5 , then add the equations.
Q. Which of these strategies would eliminate a variable in the system of equations?{x−2y=115x+3y=−11Choose 1 answers:(A) Multiply the top equation by 5 , then add the equations.(B) Add the equations.(C) Multiply the top equation by −5 , then add the equations.
Analyze coefficients: Analyze the coefficients of the variables in both equations to determine which variable can be eliminated with the least amount of manipulation.The first equation is x−2y=11 and the second equation is 5x+3y=−11. To eliminate a variable, we need to make the coefficients of either x or y opposites in both equations.
Evaluate option A: Evaluate option A: Multiply the top equation by 5, then add the equations.If we multiply the first equation by 5, we get 5(x−2y)=5(11), which simplifies to 5x−10y=55. Adding this to the second equation (5x+3y=−11) would not eliminate any variable because the coefficients of x are the same and the coefficients of y are not opposites.
Evaluate option B: Evaluate option B: Add the equations.If we add the equations as they are, we get (x−2y)+(5x+3y)=11−11, which simplifies to 6x+y=0. This does not eliminate any variable.
Evaluate option C: Evaluate option C: Multiply the top equation by −5, then add the equations.If we multiply the first equation by −5, we get −5(x−2y)=−5(11), which simplifies to −5x+10y=−55. Adding this to the second equation (5x+3y=−11) would eliminate the variable x because the coefficients of x are now opposites.
Perform operation from option C: Perform the operation from option C to confirm that it eliminates the variable x.(−5x+10y)+(5x+3y)=−55−11, which simplifies to 0x+13y=−66. The variable x has been eliminated, confirming that option C is the correct strategy.
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