Question

Questão 1-) Calcule o valor das expressões
a-) x - y, sendo x = -2 e y = -1
b-) 2x2 + 3y3 – 2xy; sendo x = 3 e y = -2
C-) – 3x2 + 4xyz - 2z; sendo x = 2 ; y = -3; z = -2 d-) 2x + 3y – 2z, sendo x = 3; y = 2 e z= -5
e-) 3xyz – 2yzx + 4xzy sendo x = 2; z=1 e y = -1​

Answer 1

Resposta:

a-) x - y, sendo x = -2 e y = -1

$- 2 - ( - 1) \\ - 2 + 1 \\ = - 1$

b-) 2x2 + 3y3 – 2xy; sendo x = 3 e y = -2

$2 \times {(3)}^{2} + 3 \times {( - 2)}^{3} - 2 \times 3 \times ( - 2) \\ 2 \times 9 + 3 \times ( - 8) + 12 \\ 18 - 24 + 12 \\ - 6 + 12 \\ = 6$

C-) – 3x2 + 4xyz - 2z; sendo x = 2 ; y = -3; z = -2

$- 3 \times {(2)}^{2} + 4 \times 2 \times ( - 3) \times ( - 2) - 2 \times ( - 2) \\ - 3 \times 4 - 24 \times ( - 2) + 4 \\ - 12 + 48 + 4 \\ 36 + 4 \\ = 40$

d-) 2x + 3y – 2z, sendo x = 3; y = 2 e z= -5

$2 \times 3 + 3 \times 2 - 2 \times ( - 5) \\ 6 + 6 + 10 \\ 12 + 10 \\ = 22$

e-) 3xyz – 2yzx + 4xzy sendo x = 2; z=1 e y = -1

$3 \times 2 \times 1 \times ( - 1) -2 \times ( - 1) \times 1 \times 2 + 4 \times 2 \times 1 \times ( - 1) \\ 6 - 32 \\ = - 26$