Question

14) Nas expressões numéricas, resolva através da propriedade distributiva em cada caso:
a) 2 . (3 – 5) =
b) 4 . (3 – 2) + 5. (7 + 1) =

1) Resolva as equações:
a) 2x – 4 + 3(x – 4) = 9
b) 4(x – 1) + 5 = x + 15
faz o calculo por favor to em prova

Answer 1

Iremos resolver através da propriedade distributiva:

1.

$ITEM \ A : \\\\ \Rightarrow \ \ \ 2 \ (3 \ - \ 5) \\\\ \Rightarrow \ \ \ 6 \ - \ 10 \\\\ \Rightarrow \ \ \ \boxed{ \ -4 \ }$          

$ITEM \ B: \\\\ \Rightarrow \ \ \ 4 \ (3 \ - \ 2) \ + \ 5 \ (7 \ + \ 1) \\\\ \Rightarrow \ \ \ 12 \ - \ 8 \ + \ 35 \ + \ 5 \\\\ \Rightarrow \ \ \ 4 \ + \ 40 \\\\ \Rightarrow \ \ \ \boxed{ \ 44 \ }$

2.

$ITEM \ A : \\\\ \Rightarrow \ \ \ 2x \ - \ 4 \ + \ 3 \ (x \ - \ 4) \ = \ 9 \\\\ \Rightarrow \ \ \ 2x \ - \ 4 \ + \ 3x \ - \ 12 \ = \ 9 \\\\ \Rightarrow \ \ \ 2x \ + \ 3x \ = \ 9 \ + \ 12 \ + \ 4 \\\\ \Rightarrow \ \ \ 5x \ = \ 25 \\\\ \Rightarrow \ \ \ x \ = \ \frac{25}{5} \\\\ \Rightarrow \ \ \ \boxed{ \ x \ = \ 5 \ }$

$ITEM \ B : \\\\ \Rightarrow \ \ \ 4 \ (x \ - \ 1) \ + 5 \ = \ x \ + \ 15 \\\\ \Rightarrow \ \ \ 4x \ - \ 4 \ + \ 5 \ = \ x \ + \ 15 \\\\ \Rightarrow \ \ \ 4x \ - \ x \ = \ 15 \ - \ 5 \ + \ 4 \\\\ \Rightarrow \ \ \ 3x \ = \ 14 \\\\ \Rightarrow \ \ \ x \ = \ \frac{14}{3} \\\\ \Rightarrow \ \ \ \boxed{ \ x \ = \ 4,666... \ }$