Answer:
From the given strategies , we can choose option B for eliminating variables .
Step-by-step explanation:
Given as :
The two linear equation
2 x - 5 y = 13 .......A
- 3 x + 2 y = 13 .......B
Now, According to question
A ) Subtract bottom equation from top equation
(- 3 x + 2 y) - (2 x - 5 y) = 13 - 13
Or, (- 3 x - 2 x) + (2 y + 5 y) = 0
Or, - x + 7 y = 0
So, From calculation we get that variables are not eliminated
Again
B) Multiply the top equation by 3 , multiply the bottom equation by 2, then add the equation
3 × (2 x - 5 y) + 2 × ( - 3 x + 2 y) = 3 × 13 + 2 × 13
Or, 6 x - 15 y - 6 x + 4 y = 39 + 26
Or, (6 x - 6 x) + (- 15 y + 4 y) = 65
Or, 0 - 11 y = 65
∴ y = [tex]\frac{65}{- 11}[/tex]
Put the value of y in eq A
∵ 2 x - 5 y = 13
Or, 2 x = 13 + 5 y
Or, 2 x = 13 + 5 ( [tex]\frac{65}{- 11}[/tex])
Or, x = [tex]\frac{-91}{11}[/tex]
So, while applying this condition we can eliminate variables
Again
C) Multiply the top equation by 2 , multiply the bottom equation by 3, then add the equation
2 × (2 x - 5 y) + 3 × ( - 3 x + 2 y) = 2 × 13 + 3 × 13
Or, 4 x - 10 y - 9 x + 6 y = 26 + 39
Or, (4 x - 9 x) + (- 10 y + 6 y) = 65
Or, - 13 x - 4 y = 65
So, while applying this condition we can not eliminate variable
Hence, From the given strategies , we can choose option B for eliminating variables . Answer
