Question

Solve the pair of equations :
2/x + 3/y = 11 , 5/x - 4/y = -7
Hence, find the value of 5x - 3y.​

Answer 1

The value of 5x - 3y will be 12 -

• 2/x + 3/y =11         (1)
• 5/x -4/y=-7             (2)
• Multiplying 1 by 7 and 2 by 11, we get -
• 14/x + 21/y = 77     (3)
• 55/x-44/y=-77       (4)
• Taking LCM and multiplying 3 and 4 with xy, we get
• 14y+21x=77xy      (5)
• 55y-44x=-77xy     (6)
• Adding 5 and 6, we get
• 69y-23x=0
• 3y=x
• Putting value of x in 5, we get
• 14y + 63y = 77y²
• 77y=77y²
• y=1
• therefore, x = 3
• Hence, Value of 5x-3y = 15-3 = 12

Answer 2

Step-by-step explanation:

Given Solve the pair of equations :  2/x + 3/y = 11 , 5/x - 4/y = -7

• Given 2/x + 3/y = 11 and 5/x – 4/y = - 7
• We need to solve the given simultaneous equations.
• So   2/x + 3/y = 11 multiply by 5
•       5/x – 4/y = - 7 multiply by 2
• So we get     10/x + 15/y = 55
•                     10/x – 8/y = - 14
• Upon subtracting we get
•                    15/y + 8/y = 69
•                    69y = 23
•                Or y = 23/69
•                Or y = 1/3
•  Now 2/x + 3/y = 11  
•          2/x + 3/1/3 = 11
•           2/x + 9 = 11
•          2/x = 2
•       Or x = 1
• Now 5x – 3y will be 5(1) – 3(1/3) = 5 – 1 = 4

Reference link will be

https://brainly.in/question/15932003