Question

solve for x and y :ax+by=k;cx-dy=l​

Answer 1

Step-by-step explanation:

I am going to tell you the method of elemination of a variable for solving these equations.

ax+by=c

cx+dy=e

Multiply the first equation with c and the second equation with a and then subtrav one equation from the other. This way the coefficient of x will become same in both the equations, hence on subtraction, x will be eliminated.

(ax+by=c)×c

(cx+dy=e)×a

_____________

acx+bcy=c²

acx+ady=ae

- - -

0 + (bc -ad)y= c²-ae

y = (c²-ae)/(bc -ad)

Now, from any one equation, calculate x in terms of y. From first equation,

x = (c-by)/a

Now, put the value of y obtained above and calculate x.

This is how you can solve a pair of linear equations in two variables by method of elimination.