Respuesta :

Answer:

See below,

Step-by-step explanation:

a) mx - ny = n

y = x

Substitute y = x in the first equation:

mx - nx = n

x(m - n) = n

x = n / (m -n).

y = n / (m - n). (ANSWER)

b)  mx + y = m

x = y + m/n

Substitute for x in the first equation:

m(y + m/n) + y = m

my + n + y = m

y(m + 1) = m - n

y = (m - n)/ ( m + 1). (ANSWER)

Substitute for y in the second equation:

x =  (m - n)/ ( m + 1)  + m/n

x =  [n(m - n)  + m(m + 1)] / n(m + 1)

x = (nm - n^2 + m^2 + m)  / ( nm + n). (ANSWER).