Question

Se P(x) = 3x ao quadrado +12x -7 então quanto é P (-1)?

Answer 1

Boa tarde

Basta substituir o -1 no lugar de x, veja:

P(-1)= 3(-1)²+12(-1)-7
P(-1)= 3-12-7
P(-1)= -16

Answer 2

Dada a função:

$\mathsf{P\left(x\right)=3x^2+12x-7}$

Substituindo $x=-1$ teremos:

$\mathsf{P\left(-1\right)=3\left(-1\right)^2+\left[12\cdot \:\left(-1\right)\right]-7}\\\\\mathsf{P\left(-1\right)=\left(3\cdot 1\right)-12-7}\\\\\mathsf{P\left(-1\right)=3-12-7}\\\\\mathsf{P\left(-1\right)=3-19}\\\\\boxed{\mathsf{P\left(-1\right)=-16}}\: \: \checkmark$