How to solve each of the following pairs of simultaneous equations for x and y? 1) ax + y = c and x+by=d

1 Answer
Jan 23, 2018

x=(d-bc)/(1-ab) and y=(c-ad)/(1-ab)

Explanation:

The best way is to use substitution method. We get y from first equation and put its value from it in second equation to get x.,

As ax+y=c, we have y=c-ax

putting this value in second equation we get

x+b(c-ax)=d

or x+bc-abx=d

or x(1-ab)=d-bc

i.e. x=(d-bc)/(1-ab)

Hence y=c-axx(d-bc)/(1-ab)

= ((c-abc-ad+abc))/(1-ab)

i.e. y=(c-ad)/(1-ab)