Question

(15x -17y = 21; 77x -15y = 11)​

Answer 1

Answer:

✪ Correct question :-

15x - 17y = 21 and 17x - 15y = 11 by elimination method.

15x - 17y = 21 . . . . . (1)

17x - 15y = 11 . . . . . (2)

Multiply equation (1) by 15 and (2) by 17, we get

225x - 255y = 315 . . . . (3)

289x - 255y = 187 . . . . (4)

Adding (3) and (4) we get,

225x - 255y = 315

289x - 255y = 187

(-) (+) (-)

___________________

- 64x = 128

x = 128/- 64

x = - 2

Substituting the value of x = - 2 in equation (1) we get,

15x - 17y = 21

➩ 15(- 2) - 17y = 21

➩ - 30 - 17y = 21

➩ - 17y = 21 + 30

➩ - 17y = 51

➩ y = 51/- 17

➩ y = - 3

∴ The value of x = - 2, y = - 3 is the solution of the system of the given equations.