Question

O valor númerico da expressão abaixo é igual a:
A) 3/2
B) 5/4
C) -3/2
D) -5/4

Answer 1

D) -5/4

$[x^3+2y]\div [x-y]=$

$[(\frac{1}{2})^3+2\cdot (-1)]\div [\frac{1}{2}-(-1)]=$

$[\frac{1}{8}-2]\div [\frac{1}{2}+1]=$

$[\frac{1}{8}-\frac{16}{8}]\div [\frac{1}{2}+\frac{2}{2}]=$

$-\frac{15}{8}\div \frac{3}{2}=$

$-\frac{15}{8}\cdot \frac{2}{3}=$

$-\frac{30}{24}=$

$\boxed{-\frac{5}{4}}$

Answer 2

Resposta:

$39.\\ \\ \\ \frac{x^{3}+2y }{x-y} \\ \\ para:\\ \\ x=\frac{1}{2}\\ \\ y=-1\\ \\ \\ \frac{(\frac{1}{2})^{3}+2.(-1) }{\frac{1}{2}-(-1) } =\\ \\ \\ \frac{\frac{1}{8}-2 }{\frac{1}{2}+1 } =\frac{\frac{1-16}{8} }{\frac{1+2}{2} } =\frac{\frac{-15}{8} }{\frac{3}{2} } =-\frac{15}{8} :\frac{3}{2} =\\ \\ \\ -\frac{15}{8} *\frac{2}{3} =-\frac{30}{24} =-\frac{5}{4} \\ \\ \\ resposta=-\frac{5}{4}$

Alternativa D) -5/4