Hello there!
To find the zeroes or the roots of a function, you just need to set the function equal to 0 then solve for x
f(x) = 2x² - 8x - 10
Set function equal to 0
2x² - 8x - 10 = 0
Now we can factorize the left side
2(x + 1)(x - 5) = 0
Then set factors equal to 0
x + 1 = 0 or x - 5 = 0
x = 0 - 1 or x = 0 + 5
x = -1 or x = 5
Thus,
The roots are -1 and 5
Let me know if you have any questions. As always, it is my pleasure to help students like you~!