Question

If 19x – 17y = 55 and 17x – 19y = 53, then the value of x – y is​

Answer 1

Answer :

We use the method of adding and subtracting.

19x - 17y = 55 -------1

17x - 19y = 53 -------2

eq1 + eq2

36x - 36y = 108

36 (x - y) = 108

x - y = 3 --------eq3

eq1 - eq2

2x - 2y = 2

2 (x - y) = 2

x + y = 2 --------eq4

from 3 and 4 by elimination

x - y = 3

x + y = 1

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2x = 4

x = 2

x + y = 1

y = 1 - x

y = 1 - 2

y = - 1

x - y = 1

2 - 1 = 1