factoring polynomial with 4 terms

[zuni18]

15x^4-12x^3+18x-7

I've tried grouping but it doesn't work. Or maybe i'm doing it wrong i don't know.

 

[MarkFL]

Have you tried applying the rational roots theorem?

 

[zuni18]

No I haven't, but I'll try it. Thank you

 

[Bob Brown MSEE]

Irrational Roots

This Polynomial has only 2 real roots.
x1 = 1.5513303138231169763164622987965706141130247800476159073288332738095994077079762520155032513003929680201958650383262

and

x2 = -1.4209377937951188501853713050644975573648965234413302921569889639681967179342541952373791987067047058800422366753381

Their sum does not seem to repeat and is likely irrational.
x1+x2 = 0.130392520027998126131090993732073056748128256606285615171844309841402689773722056778124052593688262140153628362988