Answer
x=-2.5 or 2.5
Work Step by Step
Factor the binomial using the formula for factoring a difference of squares.
4x$^2$-25=0
(2x+5)(2x-5)=0
Set each variable factor as equal to zero and then isolate the variable to find the solutions.
2x+5=0 or 2x-5=0
2x=-5 or 2x=5
x=-2.5 or x=2.5
Enter the equation into your graphing utility to observe that the graph crosses the x-axis at -2.5 and 2.5