Question

determine o valor numerico de cada expressão algébrica:
a)-1 elevado a 3 +2 vezes -1 elevado a 2 +(-1)+1

b)-1 elevado a 3 +3 vezes -1 vezes 1 elevado a 2 + 1 elevado a 2

c)1/3+3

d)x/x+y para x =1/2 e y =1/3

Answer 1

$a)~~(-1)^3+2.(-1)^2+(-1)+1\to~~-1+2.1-1+1\to\\\\-1+2-1+1\to~~ -2+3\to~~\boxed{1}\\\\\\\\ b)~~(-1)^3+3.(-1).1^2+1^2\to~~ -1-3.1+1\to~~-1-3+1\to~~\boxed{-3}\\\\\\\\ c)~~ \dfrac{1}{3} +3\to~~ \dfrac{1+9}{3} \to~~ \boxed{ \frac{10}{3} }$



$d)~~Para\to~x= \dfrac{1}{2} ~~e~~ y=\dfrac{1}{3} \\\\\\ \dfrac{x}{x+y} \to~~ \dfrac{ \dfrac{1}{2} }{\dfrac{1}{2}+\dfrac{1}{3}} \to~~ \dfrac{ \dfrac{1}{2} }{\dfrac{3+2}{6}} \to~~ \dfrac{ \dfrac{1}{2} }{\dfrac{5}{6}} \to~~ \dfrac{ 1 }{2}\times \dfrac{ 6 }{5} \to~~ \dfrac{6}{10} \to~~ \boxed{\dfrac{ 3 }{5}}$