Question

9x+4y=5,4x-5y=9.solve the equation simultaneously
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Answer 1

Answer:

Check the above attachment

Answer 2

EXPLANATION.

⇒ 9x + 4y = 5. - - - - - (1).

⇒ 4x - 5y = 9. - - - - - (2).

Multiply equation (1) by 5.

Multiply equation (2) by 4.

⇒ 9x + 4y = 5. - - - - - (1).  x  5.

⇒ 4x - 5y = 9. - - - - - (2).  x  4.

We get,

⇒ 45x + 20y = 25. - - - - - (3).

⇒ 16x - 20y = 36. - - - - - (4).

Adding equation (3) and equation (4), we get.

⇒ (45x + 20y) + (16x - 20y) = 25 + 36.

⇒ 45x + 20y + 16x - 20y = 25 + 36.

⇒ 45x + 16x = 25 + 36.

⇒ 61x = 61.

⇒ x = 1.

Put the value of x = 1 in equation (1), we get.

⇒ 9x + 4y = 5. - - - - - (1).

⇒ 9(1) + 4y = 5.

⇒ 9 + 4y = 5.

⇒ 4y = 5 - 9.

⇒ 4y = - 4.

⇒ y = - 1.

∴ value of x is 1  and  y is - 1.