Answer:
y = x² + 38x + 311
Step-by-step explanation:
If a polynomial has rational coefficients and irrational roots, then the roots must be conjugate pairs.
y = (x − (-19-5√2)) (x − (-19+5√2))
y = (x + 19+5√2) (x + 19−5√2)
Use FOIL to distribute:
y = x² + x (19−5√2) + x (19+5√2) + (19+5√2)(19−5√2)
y = x² + 19x − 5√2 x + 19x + 5√2 x + (19+5√2)(19−5√2)
y = x² + 38x + (19+5√2)(19−5√2)
Use FOIL to distribute the last term:
y = x² + 38x + 19² − 95√2 + 95√2 − 50
y = x² + 38x + 361 − 50
y = x² + 38x + 311
