Question

5/x+6y=13,3/x+4y=7 substitution method

Answer 1

Answer:

The given equations are:  

5/x + 6y = 13 ……..

(i)  3/x + 4y = 7 ……..

(ii)  Putting 1/x = u,

we get: 5u + 6y = 13 …….

(iii)  3u + 4y = 7 ……

(iv)  On multiplying

(iii) by 4 and

(iv) by 6, we get:  20u + 24y = 52 …….

.(v)  18u + 24y = 42 ……..

(vi)  On subtracting

(vi) from

(v), we get:  2u = 10 ⇒ u = 5  ⇒ 1/x = 5  ⇒ x = 1/5  

On substituting x = 1/5 in

(i), we get:  5/ 1/3 ⁄ + 6y = 13  25 + 6y = 13  6y = (13 – 25) = -12  y = -2

Hence, the required solution is x = 1/5 and y = -2