Question

If 3x + 5y = 9 and 5x + 3y =7, then find the value of x+y​

Answer 1

Answer:

X= - 426 Y= 19/2

Step-by-step explanation:

3x + 5y = 9 -1

5x + 3y = 7 -2

so,

by substitution method ,

3x + 5y = 9

3x = 9 - 5y

x = 9 - 5y/3. - 3

substitution x value in eqn 2

5x + 3y = 7

5 × 9 - 5y/3 +3y = 7

45 - 5y + 3y×3 = 7

45 - 5y + 9y = 7

4y = 7 - 45

4y = 38

y = 38/4

y= 19/2

Now substituting the value of y in eqn 3

X = 9- 5y/3

X= 9 -5×19/2/3

X= 9 - 19 /2/3

X= 9 - 285×2/3

X = 9 - 855/2

X = 846 / 2

X = -426