Question

10y - 5 (1 + y) = 3 (2y - 2) - 20 Me ajudem por favor pls.

Answer 1

10y-5-5y=6y-6-20
5y-6y=-26+5
(-y=-21)×(-1)
y=21

Answer 2

Operação:
$\mathrm{Expandir\:}10y-5\left(1+y\right):\quad 5y-5$
$\mathrm{Expandir}\:-5\left(1+y\right):\quad -5-5y$
$-5\left(1+y\right)$

$\mathrm{Colocar\:os\:parenteses\:utilizando}:\quad \:a\left(b+c\right)=ab+ac$
$a=-5,\:b=1,\:c=y$
$=-5\cdot \:1-5\cdot \:y$


$\mathrm{Multiplicar\:os\:numeros:}\:5\cdot \:1=5$
$=-5-5y$

$=10y-5-5y$


$\mathrm{Simplificar}\:10y-5-5y:\quad 5y-5$
$10y-5-5y$

$\mathrm{Agrupar\:termos\:semelhantes}$
$=10y-5y-5$


$\mathrm{Somar\:elementos\:similares:}\:10y-5y=5y$
$=5y-5$



$\mathrm{Expandir\:}3\left(2y-2\right)-20:\quad 6y-26$
$3\left(2y-2\right)-20$
$\mathrm{Expandir}\:3\left(2y-2\right):\quad 6y-6$

$3\left(2y-2\right)$

$\mathrm{Colocar\:os\:parenteses\:utilizando}:\quad \:a\left(b+c\right)=ab+ac$
$a=3,\:b=2y,\:c=-2$
$=3\cdot \:2y+3\left(-2\right)$

$\mathrm{Aplicar\:as\:regras\:dos\:sinais}$
$+\left(-a\right)=-a$
$=3\cdot \:2y-3\cdot \:2$


$\mathrm{Multiplicar\:os\:numeros:}\:3\cdot \:2=6$
$=6y-6$


$=6y-6-20$

$\mathrm{Subtrair:}\:-6-20=-26$
$=6y-26$

$5y-5=6y-26$

$\mathrm{Adicionar\:}5\mathrm{\:a\:ambos\:os\:lados}$
$5y-5+5=6y-26+5$

$\mathrm{Simplificar}$
$5y=6y-21$


$\mathrm{Subtrair\:}6y\mathrm{\:de\:ambos\:os\:lados}$
$5y-6y=6y-21-6y$

$\mathrm{Simplificar}$
$-y=-21$

$\mathrm{Dividir\:ambos\:os\:lados\:por\:}-1$
$\frac{-y}{-1}=\frac{-21}{-1}$

$\mathrm{Simplificar}$
$y=21$