Question

x/y=7/9
x-y=6
aflati x, y


a/2=b/4=c/6
a+2xc=7
a,b,c=?



​

Answer 1

Salut! =)

1 )

x / y = 7 / 9

x - y = 6

-----------------------

x , y = ?

7y = 9x

x = 7y / 9

Inlocuim in a doua formula

7y / 9 - y = 6 ( Aducem la acelasi numitor )

7y - 9y = 54

-2y = 54

y = -27

x = -21

2 )

a / 2 = b / 4 = c / 6

a + 2c = 7

--------------------------

a , b , c =?

a / 2 = c / 6 => a = c / 3

Inlocuim in a doua formula

c / 3 + 2c = 7 ( Aducem la acelasi numitor )

c + 6c = 21

7c = 21 => c = 3

a = c / 3 => a = 1

a / 2 = b / 4

1 / 2 = b / 4 => b = 2

Bafta! =)