Question

5x elevado a 3- 2x elevado a 2 +5 para x=-1

Answer 1

${5x}^{3} - {2x}^{2} + 5 = 0 \\ 3x + 5 = 0 \\ x = \frac{5}{3}$

Answer 2

$5{x}^{3} - 2 {x}^{2} + 5 \\se \: x = - 1 \\ temos \: que\\ 5.( { - 1}^{3} ) = 5. - 1 = - 5 \\ 2.( - 1) {}^{2} = 2.1 = 2 \\ logo \\ - 5 - 2 + 5 = - 2$