Math, asked by shivirana, 11 months ago

2/x+3/y=13
5/x-4/y=-2
Solve the equations by elimination and verify it by cross multiplication.....
Plz ans as soon as possible..

Answers

Answered by Devasam
9

Answer:

2/x + 3/y = 13

5/x - 4/y = - 2

Answer

Putting 1/x = a and 1/y = b are reduce to

2a + 3b = 13 equation 1

5a - 4b = - 2 equation 2

By the elimination method

equation 1 is multiplied by 5 and equation 2 is multiplied by 2 are as follows ___

10a + 15b = 65 equation 3

10a - 8b = -4 equation 4

Now

By subtracting the equation 4 from equation 3 , we get

(10a-10a) + (15b + 8b) = 65 + 4

= 0 + 23b = 69

= b = 69/23 = 3

Now

putting b=3 in the equation

3 we get

10a + 15 × 3 = 65

10a + 45 = 65

10a = 65-45

a = 20/10 = 2

The reqd. solution is

since a=2 and b=3

Therefore we get

1/x=a and 1/y=b

So

NOW

1/x = 2 and 1/y = 3

2x = 1 and 3y = 1

x = 1/2 and y = 1/3

Hope this answer give you more knowledge

Answered by Siddharta7
21

Step-by-step explanation:

Given,

2/x + 3/y = 13 ----(1)

5/x - 4/y = -2 ------(2)

Let 1/x = a and 1/y = b , We get

2a+3b=13 -----(3)

5a-4b = -2 -----(4)

On solving (3) * 4 & (4) * 3, we get

8a + 12b = 52

15a - 12b = -6

----------------------

23a = 46

=> a = 2

Substitute the value of a in equation (3), we get

=> 4 + 3b = 13

=> 3b = 13 - 4

=> 3b = 9

=> b = 9/3

=> b = 3

But 1/x = a = 2 => x = 1/2

1/y = b = 3 => y = 1/3

Thus,

x = (1/2), y = (1/3)

Verification :

Formula is :

[x/(b₁c₂ - b₂c₁) = y/(c₁a₂ - c₂a₁) = 1/(a₁b₂ - a₂b₁)]

On transposition, we get

2a + 3b - 13 = 0

5a - 4b + 2 = 0

By cross-multiplication method:

x/(3 * 2 - (-4)(-13)) = y/(-13 * 5 - 2 * 2) = 1/(2 * -4 - 5 * 3)

=> -x/46 = -y/69 = 1/-23

=> -x/46 = -1/23 and -y/69 = -1/23

=> x = 1/2, y = 1/3

Thanks for Blocking dear!

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