Use substitution to solve each of the following pairs of simultaneous equations for x and y in terms of m and n.

a) mx + y = n

y = mx

b) x + ny = m

y = nx

c) mx - y = n

y = nx

d) mx - ny = n

y = x

e) mx + y = m

x = y + m/n

Step-by-step explanation:

a)

As given y=mx lets replace mx with y in the first equation

2y=n = > y=n/2, replace y with n/2 = > mx=n/2, thus x=n/2m

b)

As given y=nx lets replace y with nx in the first equation

x+n^2x=m = > x (n^2+1) = m = > x=m / (n^2+1), thus y = n*m / (n^2+1)

c) Replace y with nx = > mx-nx=n = > x (m-n) = n = > x=n / (m-n), thus y=n^2 / (m-n)