A variable needs to be eliminated to solve the system of equations below. Choose the correct first step.−2x+10y=72−6x+10y=36Add to eliminate y.Subtract to eliminate x.Add to eliminate x.Subtract to eliminate y.
Q. A variable needs to be eliminated to solve the system of equations below. Choose the correct first step.−2x+10y=72−6x+10y=36Add to eliminate y.Subtract to eliminate x.Add to eliminate x.Subtract to eliminate y.
Analyze Coefficients: Analyze the coefficients of the variables in both equations.We have the system of equations:−2x+10y=72−6x+10y=36To eliminate a variable, we need to make the coefficients of either x or y the same with opposite signs so that addition or subtraction will cancel out that variable.
Compare Coefficients: Compare the coefficients of x and y in both equations.The coefficients of y are already the same (10 and 10), but the coefficients of x are not the same (−2 and −6). To eliminate y, we would need to multiply the first equation by a factor that would make the coefficient of y in the first equation the opposite of the coefficient of y in the second equation. However, since the coefficients of y are already the same, we can simply subtract one equation from the other to eliminate y.
Decide Operation: Decide on the operation to eliminate y. Since the coefficients of y are the same, we can subtract the second equation from the first to eliminate y. −2x+10y=72 - (−6x+10y=36) This will result in: −2x+10y−(−6x+10y)=72−36
Perform Subtraction: Perform the subtraction to check if y is eliminated.−2x+10y−(−6x+10y)=72−36 simplifies to:−2x+10y+6x−10y=72−36 The terms +10y and −10y cancel each other out, leaving:4x=36
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