Question

caulcule o valor do y: x= 3y
a) x+y=6
b)4X+2Y=15
c) 10x-y=58
d)x/2+y/2=5/6
e)10.(x-y)=200

me ajudem pfv nessa lição​

Answer 1

Olá....

Resolução:

Substitua o x pelo valor informado.

Sendo: x = 3y

a)

3y + y = 6

4y = 6

y = 6/4 ÷ 2

y = 3/2

b)

4.( 3y) + 2y = 15

12y + 2y = 15

14y = 15

y = 15/14

c)

10.( 3y) - y = 58

30y - y = 58

29y = 58

y = 58/29

y = 2

d)

3y/2 + y/2 = 5/6 ⇒mmc de 2, 2, 6 = 6

9y + 3y = 5

12y = 5

y = 5/12

e)

10.(3y - y) = 200

30y - 10y = 200

20y = 200

y = 200/20

y = 10

Bons estudos.

Answer 2

a)

$3y+y=6 \\ 4y=6 \\y=\frac{6\div2}{4\div2} \\y=\frac{3}{2}$

b)

$4x+2y=15 \\ 4.3y+2y=15 \\ 12y+2y=15 \\ 14y=15 \\ y=\frac{15}{14}$

c)

$10x-y=58 \\ 10.3y-y=58 \\30y-y=58 \\29y=58 \\ y=\frac{58}{29} \\ y=2$

d)

$\frac{x}{2}+\frac{y}{2}=\frac{5}{6} \\ \frac{3y}{2}+\frac{y}{2}=\frac{5}{6}$

$\frac{9y+3y=5}{6} \\ 12y=5 \\ y=\frac{5}{12}$

e)

$10.(x-y)=200 \\ x-y=\frac{200}{10} \\ x-y=20$

$3y-y=20 \\2y=20 \\y=\frac{20}{2} \\ y=10$