Question 851954
Try factoring negative 1 and then make trials to test multiply.

{{{-1(5x^2-2x-16)}}} and just focus on the quadratic factor, and try to factor it.


{{{(5x+a)(x+b)=5x^2+5bx+ax+ab=5x^2+(5b+a)x+ab}}}
This should mean that 5b+a=-2 and ab=-16 but this does not make the process any easier.


Try different combinations.
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(5x__2)(x__8)---------- 2 and 40; and 16
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(5x__8)(x__2)--------- 10 and 8; and 16.  Maybe.
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(5x__4)(x__4)--------- 20 and 4; and 16
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The combination that works including which operations in each binomial factor is
{{{(5x-8)(x+2)}}}, and since you started with a factor of negative 1, your factorization can be:
{{{highlight((-1)(5x-8)(x+2))}}}.