Question

5x+7y=21 and 7x+5y=15 then find the value of x+y

Answer 1

Answer:

7(5x+7y=21) = 35x+49y=147

5(7x+5y=15) = 35x+25y=75

By adding both the equations we get,

24y = 72

or, y = 72/24

or, y = 3

Putting the value of y in first equation we get,

5x+7(3) = 21

or, 5x = 21 - 21

or, x = 0/5

or, x = 0

Therefore, x+y = 0+3 = 3

Step-by-step explanation:

Hope this helps.