Question

if 2x +4y = 500 then find the 7x + 12y = ?​

Answer 1

Here is the solution.....

since,

2x + 4y = 500

2x + 4y = 5002(x + 2y) = 500

Therefore....

x + 2y = 250

x + 2y = 250x = 250 - 2y............(i)

Now,

7x + 12y = ?

let (7x + 2y) be ........(ii)

Now, put (i) in (ii)

Therefore,

=7(250 - 2y) + 12y

=7(250 - 2y) + 12y =1750 - 14y + 12y

=7(250 - 2y) + 12y =1750 - 14y + 12y=1750 = 2y

=7(250 - 2y) + 12y =1750 - 14y + 12y=1750 = 2yy = 1750/2

=7(250 - 2y) + 12y =1750 - 14y + 12y=1750 = 2yy = 1750/2y = 875

so,