Resposta :
n²-3n-28=0
Δ=(-3)²-4.1.-28
Δ=9+112
Δ=121
[tex]n= \frac{3+- \sqrt{121} }{2}\\\\ n=\frac{3+-11}{2} \\\\n'= \frac{3+11}{2} \\\\n'= \frac{14}{2} \\\\n'=7\\\\n" \frac{3-11}{2} n" \frac{-8}{2}\\\\n"=-4[/tex]
Δ=(-3)²-4.1.-28
Δ=9+112
Δ=121
[tex]n= \frac{3+- \sqrt{121} }{2}\\\\ n=\frac{3+-11}{2} \\\\n'= \frac{3+11}{2} \\\\n'= \frac{14}{2} \\\\n'=7\\\\n" \frac{3-11}{2} n" \frac{-8}{2}\\\\n"=-4[/tex]