Question

$5\left(x+3\right)=10\left(x-1\right)$ me ajudem

Answer 1

5 (x+3) = 10 (x-1)
5x+15=10x-10
15+10= 10x - 5x
25 = 5x
x = 25 / 5
x = 5

Answer 2

Olá boa tarde, Titoyui
Sua dúvida é bem simples veja,

$\mathrm{Expandir\:}5\left(x+3\right):\quad 5x+15$
$5\left(x+3\right)$


$\mathrm{Colocar\:os\:parenteses\:utilizando}:\quad \:a\left(b+c\right)=ab+ac$
$a=5,\:b=x,\:c=3$
$=5\cdot \:x+5\cdot \:3$


$\mathrm{Multiplicar\:os\:numeros:}\:5\cdot \:3=15$
$=5x+15$


$\mathrm{Expandir\:}10\left(x-1\right):\quad 10x-10$
$10\left(x-1\right)$


$\mathrm{Colocar\:os\:parenteses\:utilizando}:\quad \:a\left(b+c\right)=ab+ac$
$a=10,\:b=x,\:c=-1$
$=10\cdot \:x+10\left(-1\right)$

$\mathrm{Aplicar\:as\:regras\:dos\:sinais}$
$+\left(-a\right)=-a$

$\mathrm{Multiplicar\:os\:numeros:}\:10\cdot \:1=10$
$=10x-10$


$5x+15=10x-10$


$\mathrm{Subtrair\:}15\mathrm{\:de\:ambos\:os\:lados}$
$5x+15-15=10x-10-15$


$\mathrm{Simplificar}$
$5x=10x-25$

$\mathrm{Subtrair\:}10x\mathrm{\:de\:ambos\:os\:lados}$
$5x-10x=10x-25-10x$

$\mathrm{Simplificar}$
$-5x=-25$


$\mathrm{Dividir\:ambos\:os\:lados\:por\:}-5$
$\frac{-5x}{-5}=\frac{-25}{-5}$


$\mathrm{Simplificar}$
$x=5$