Question

Calcule o valor das expressões: para x=3 e y=2

a) 3x² + 5y=

b) 5y - 4x² + 7y=

c) -8y +5² + x =

d) -6x² +9y+15=

e) -25x-1+ 4y =

f)-2y³-40x-23x
me ajudem pfv ​

Answer 1

Resposta:

a) 3x² + 5y=

${3x}^{2} + 5y \\ 3 \times {3}^{2} + 5 \times 2 \\ 3 \times 9 + 10 \\ 27 + 10 = 37$

b) 5y - 4x² + 7y=

$5y - {4x}^{2} + 7y \\ 5 \times 2 - 4 \times {3}^{2} + 7 \times 2 \\ 5 \times 2 - 4 \times 9 + 7 \times 2 \\ 10 - 36 + 14 \\ - 26 + 14 = - 12$

c) -8y +5² + x =

$- 8y + 5 {}^{2} + x \\ - 8 \times 2 + 25 + 3 \\ - 16 + 28 = 12$

d) -6x² +9y+15=

${ - 6x}^{2} + 9y + 15 \\ - 6 \times 3 {}^{2} + 9 \times 2 + 15 \\ - 6 \times 9 + 9 \times 2 + 15 \\ - 54 + 18 + 15 \\ - 54 + 33 = - 21$

e) -25x-1+ 4y =

$- 25x - 1 + 4y \\ - 25 \times 3 - 1 + 4 \times 2 \\ - 75 - 1 + 8 \\ - 75 + 7 = - 68$

f)-2y³-40x-23x

${ - 2y}^{3} - 40x - 3x \\ - 2 \times {2}^{2} - 40 \times 3 - 3 \times 3 \\ - 2 \times 4 - 120 - 9 \\ - 8 - 120 - 9 \\ - 17 - 120 = - 137$