Question

Resolva
a) x^2-3x+1, para x= -4
b) a^3-b^3-2a^2+4ab+1, para a= 2, b= -3
c) x^3+2x^2+xy+2ti, para x= 3, y= -2

Answer 1

a)

${x}^{2} - 3x + 1$
$4^{2} - 3 \times (-4) + 1 \\ 16 + 12 + 1 \\ 29$
b)

${a}^{3} - b^{3} - 2 {a}^{2} + 4ab + 1 \\ {2}^{3} - {( - 3)}^{3} - 2 \times {2}^{2} + 4 \times 2 \times ( - 3) + 1 \\ 8 + 27 - 2 \times 4 + 8 \times ( - 3) + 1 \\ 35 - 8 - 24 + 1 \\ 4$

c)

${x}^{3} + 2 {x}^{2} + xy + 2y \\ {3}^{3} + 2 \times {3}^{2} + 3 \times ( - 2) + 2 × (-2) \\ 27 + 2 \times 9 - 6 -4 \\ 27 + 18 -10 \\ 35$