Question

If x+ y = 12 and x= 2 y then x. =

Answer 1

Hello!

x + y = 12

x = 2y

we replace x by 2y in the 1st equation:

x + y = 12

2y + y = 12

3y = 12

y = 12/3

y = 4

so:

x = 2y

x = 2*4

x = 8

In this system of equation, x = 8

Answer 2

x = 8

and y = 4

Explanation:

We have,

x + y = 12 (i)

x = 2y, (ii)

Then, putting the value of x from (ii) into (i),

x + y = 12

2y + y = 12

3y = 12

y = 12/3

y = 4

Now, since x = 2y,

x = 2(4)

x = 8

(also, x + y = 12, so x = 4 = 12, x = 12 -4, x = 8)