Question

2) Resolva as seguintes equações, sendo U = Q:
x
a)
= 7
2 x
3
10
3
b
b)
х
4
X
11
- 3
e)
3 x
4
= 30
2x
c)
2x
5
f)
=
18
5​

Answer 1

$\large\boxed{\begin{array}{l}\rm Resolva~as~equac_{\!\!,}\tilde oes~sendo~U=\mathbb{Q}:\\\rm a)~\dfrac{x}{3}=7\\\\\rm b)~\dfrac{x}{4}=-3\\\\\rm c)~\dfrac{2x}{5}=4\\\\\rm d)~\dfrac{2x}{3}=-10\\\\\rm e)~\dfrac{3x}{4}=30\\\\\rm f)~\dfrac{2x}{5}=-18\end{array}}$

$\boxed{\begin{array}{l}\underline{\rm soluc_{\!\!,}\tilde ao:}\\\tt a)~\sf\dfrac{x}{3}=7\\\sf x=3\cdot7\\\sf x=21\\\tt b)~\sf\dfrac{x}{4}=-3\\\sf x=4\cdot(-3)\\\sf x=-12\\\tt c)~\sf\dfrac{2x}{5}=4\\\sf 2x=5\cdot4\\\sf 2x=20\\\sf x=\dfrac{20}{2}\\\sf x=10\\\tt d)~\sf\dfrac{2x}{3}=-10\\\sf 2x=3\cdot(-10)\\\sf 2x=-30\\\sf x=-\dfrac{30}{2}\\\sf x=-15\\\tt e)~\sf\dfrac{3x}{4}=30\\\sf 3x=4\cdot30\\\sf 3x=120\\\sf x=\dfrac{120}{3}\\\sf x=40\\\tt f)~\sf\dfrac{2x}{5}=-18\\\sf 2x=5\cdot(-18)\\\sf 2x=-90\end{array}}$

$\boxed{\begin{array}{l}\sf x=-\dfrac{90}{2}\\\sf x=-45\end{array}}$