Question

Solve 6x=7y+7 and 7y-x=8 by substitution method.

Answer 1

Here the answer is......

Answer 2

Considering the equations 7y-x=8(say, equation 1) and 6x=7y+7(say, equation 2)

In equation 1,
 7y-x=8
 This gives, x=7y-8

Now in equation 2,
 6x=7y+7
Putting the value of x from equation 1 in equation 2, we get-
 6(7y-8)=7y+7
 42y-48=7y+7 42y-7y=48+7
 35y=55
 This gives, y=55/35

Further, putting this value  of y in the value of x derived from equation 1, we get-
 x=7y-8
 x=7(55/35)-8
 x=(55/5)-8
 x=(55-40)/5
 x=15/5
 x=3

Thus, the given two equations gives us the solution set as-
    x = 3 , y = 55/35
Or,
    x = 3 , y = 11/7