Question

se x=-5/2 , entao 2x + 8 vale ?

Answer 1

olá ..
x=-5/2 então 2 x=-10/2 =-5
2x+8=-5+8
-5+8=3
espero ter ajudado ..

Answer 2

Resolução da questão, veja:

$\mathsf{2x+8}}~\to~\mathsf{x=\dfrac{-5}{2}}}\\\\\\\\\\ \mathsf{2~\cdot~\bigg(\dfrac{-5}{2}\bigg)+8}}\\\\\\\\\\ \mathsf{\bigg(\dfrac{-10}{2}\bigg)+8}}~~\textsf{Tirando~o~MMC~de~1~e~2:}}\\\\\\\\\\\ \mathsf{\dfrac{-10+16}{2}}\\\\\\\\\\ \mathsf{\dfrac{6}{2}}\\\\\\\\\ \large\boxed{\boxed{\boxed{\boxed{\boxed{\mathsf{3.}}}}}}}}}}}}}}}}}}}}$

Espero que te ajude '-'