Q. Which value for the constant d makes y=20 an extraneous solution in the following equation?21y−1=43y+dd=□
Identify equation and condition: Identify the given equation and the condition for an extraneous solution.We are given the equation 21⋅y−1=43⋅y+d and we need to find the value of d that makes y=20 an extraneous solution.
Substitute y=20 into equation: Substitute y=20 into the equation to find the value of d that would make this solution extraneous.Substitute y=20 into 21⋅y−1=43⋅y+d.Equation after substitution: 21⋅20−1=43⋅20+d.
Simplify left side of equation: Simplify the left side of the equation.Simplify 21×20−1 to 10−1 which simplifies to 9.
Simplify right side of equation: Simplify the right side of the equation.Simplify (43)×20 to 15.Now the equation is 9=15+d.
Simplify square root on left side: Simplify the square root on the left side of the equation. 9 simplifies to 3. Now the equation is 3=15+d.
Solve for d: Solve for d.Subtract 15 from both sides of the equation to isolate d.3−15=dd=−12
Verify value of d: Verify if the value of d makes y=20 an extraneous solution.An extraneous solution is one that does not satisfy the original equation. Since we derived d by substituting y=20 into the equation, we need to check if this value of d leads to a contradiction when we substitute y=20 back into the original equation.
Substitute y=20 and d=−12 into original equation: Substitute y=20 and d=−12 into the original equation and check for a contradiction.Substitute y=20 and d=−12 into 21⋅y−1=(43)⋅y+d.Equation after substitution: 21⋅20−1=(43)⋅20−12.Simplify the equation: 10−1=15−12.Simplify further: 9=3.Since d=−120 is indeed d=−121, there is no contradiction, and y=20 is not an extraneous solution with d=−12. This means we made a mistake in our assumption that d=−12 would make y=20 an extraneous solution.