Question

Dado a expressão literal,
3x² - 2x + 6. Determine o seu valor
sabendo que:
a) x = 2
b) x = -1
c) x = 0
d) x = 5
e) x = -5
​

Answer 1

Resposta:

a) x = 2

${3x}^{2} - 2x + 6 \\ 3 \times {(2)}^{2} - 2 \times 2 + 6 \\ 3 \times 4 - 4 + 6 \\ 12 + 2 = 14$

b) x = -1

${3x}^{2} - 2x + 6 \\ 3 \times {( - 1)}^{2} - 2 \times ( - 1) + 6 \\ 3 \times 1 + 2 + 6 \\ 3 + 8 = 11$

c) x = 0

$3 \times {0}^{2} - 2 \times 0 + 6 \\ 3 \times 0 - 0 + 6 \\ = 6$

d) x = 5

${3x}^{2} - 2x + 6 \\ 3 \times {(5)}^{2} - 2 \times 5 + 6 \\ 3 \times 25 - 10 + 6 \\ 75 - 10 + 6 \\ 65 + 6 = 71$

e) x = -5

${3x}^{2} - 2x + 6 \\ 3 \times {( - 5)}^{2} - 2 \times ( - 5) + 6 \\ 3 \times 25 + 10 + 6 \\ 75 + 16 = 91$