Question

calcule o valor das expressões algébricas:​

Answer 1

Resposta:

$a) \: {x}^{2} - 5x + 8 \\ {(2)}^{2} - 5 \times 2 + 8 \\ 4 - 10 + 8 \\ - 6 + 8 \\ = 2$

$b \: {x}^{2} - 5x + 8 \\ {( - 2)}^{2} - 5 \times ( - 2) + 8 \\ 4 + 10 + 8 \\ = 22$

$c) \: {x}^{2} + 2xy \\ {( - 4)}^{2} + 2 \times ( - 4) \times 0 \\ {( - 4)}^{2} + 0 \\ = 16$

$d) \: {x}^{2} + 2xy \\ {( - 2)}^{2} + 2 \times ( - 2) \times 3 \\ 4 - 12 \\ = - 8$