Question

If 9x + 11y = 78 and 11x + 9y = 82 then what is the value of x + y ?

(A) 8 (B) 2 (C) 80 (D) 20.​

Answer 1

Answer:

add both the eq 20x + 20y = 160

now divide this eq by 20

x+y =8

Answer 2

Answer:

(B) 2

Step-by-step explanation:

9x +11y=78

11x +9y=82

_________

2x +2y=4

2(x+y)= 4

x+y = 2