Question 1168460
if x - 5 is a zero, then solve for x to get = 5
set the equation equal to 0 and replace x with 5 in the equation to get:


2x^4 - 5x^2 + k = 0 becomes:


2*5^4 - 5*5^2 + k = 0 which becomes:


1125 + k = 0


solve for k to get:


k = -1125


the equation becomes 2x^4 - 5x^2 - 1125 = y


when you replace x with 5, you get y = 0.


the graph of this equation looks like this.


<img src = "http://theo.x10hosting.com/2020/102805.jpg" >


it actually has 2 zeroes, one at x = -5 and one at x = 5.


it actually has 4 roots, except that 2 of them aren't real and so don't show up on the graph.


the 2 roots that are real are the zeroes.