Q. (x+4)(2x−a)=0In the given equation, a is a constant. If the equation has the solutions x=4 and x=−4, what is the value of a ?
Identify Solutions: Identify the solutions of the equation.The given equation is in factored form, which means that the solutions for x are the values that make each factor equal to zero. According to the problem, the solutions are x=4 and x=−4.
Apply First Solution: Apply the first solution to the equation.If x=4 is a solution, then substituting x=4 into the equation (x+4)(2x−a)=0 should result in a true statement. Let's substitute x=4 into the equation and see what we get.(4+4)(2⋅4−a)=0(8)(8−a)=0
Solve for a: Solve for a using the first solution.Since (8)(8−a)=0, we know that one of the factors must be zero. The first factor, 8, is not zero, so the second factor, 8−a, must be zero. Therefore, we can set 8−a=0 and solve for a.8−a=0a=8
Verify with Second Solution: Verify the solution with the second solution.Now we need to check if a=8 works for the second solution x=−4. Substitute x=−4 into the equation (x+4)(2x−a)=0 with a=8.(−4+4)(2∗(−4)−8)=0(0)(−8−8)=0(0)(−16)=0
Confirm Correct Value: Confirm that the value of a is correct.Since the second factor is zero when x=−4, the equation is satisfied. This confirms that a=8 is the correct value for a, as it works for both solutions x=4 and x=−4.
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