Q. Solve for x.(x+4)(x−4)<0Write a compound inequality like 1<x<3 or like x<1 or x>3.
Plot Zeros and Test Intervals: Plot the zeros on a number line and test the intervals. The intervals are (−∞,−4), (−4,4), and (4,∞).
Test Interval (−∞,−4): Test the interval (−∞,−4) by picking a number less than −4, say −5.(−5+4)(−5−4)=(−1)(−9)=9, which is \ (> 0 \).
Test Interval (−4,4): Test the interval (−4,4) by picking a number between −4 and 4, say 0.(0+4)(0−4)=(4)(−4)=−16, which is < 0.
Test Interval (4,∞): Test the interval (4,∞) by picking a number greater than 4, say 5.(5+4)(5−4)=(9)(1)=9, which is > 0.
Identify Solution Interval: Since we want (x + 4)(x - 4) < 0, the solution is the interval where the product is negative.The product is negative in the interval (−4,4).
Write Compound Inequality: Write the solution as a compound inequality. -4 < x < 4.