Question

me ajuder por favooooo​

Answer 1

Resposta:

a) A = -4

b) A = -11/4

Explicação passo-a-passo:

$A = 3x^2+5x-6$

a)

$x = -2$

$A=3\times(-2)^2+5\times(-2)-6\\A=3\times4-10-6\\A=12-10-6\\A=-4$

b)

$x=2^{-1}=\frac{1}{2}$

$A=3\times(\frac{1}{2})^2+5\times\frac{1}{2}-6$

$A=3\times\frac{1}{4}+\frac{5}{2}-6$

$A=\frac{3}{4}+\frac{5}{2}-6$

$A=\frac{3}{4}+\frac{10}{4}-\frac{24}{4}$

$A=\frac{3+10-24}{4}$

$A =- \frac{11}{4}$