Question

If 11x + 5y = 25 and 5x + 11y = 7 then x+y=
a) 1
b) 2
c) 3
d) 5


I want full step by step​

Answer 1

i my opinon answer is correct

Answer 2

Answer:

2

Step-by-step explanation:

11x + 5y = 25 -----(1)

5x + 11y = 7 -----(2)

Multiply equation (1) by 5,

55x + 25y = 125 ----(3)

Multiply equation (2) by 11,

55x + 121y = 77 ----(4)

Subtract equation (4) from equation (3),

55x + 25y -(55x + 121y) = 125 - 77

55x + 25y - 55x - 121y = 48

- 96y = 48

y = 48/(-96)

y = 1/(-2)

Put the value of y in equation (1),

11x + 5(1/-2) = 25

11x - 5/2 = 25

11x = 25 + 5/2

11x = (50 + 5)/2

11x = 55/2

x = 55/(2×11)

x = 5/2

x + y = 5/2 + (-1/2)

= 5/2 - 1/2

= (5 -1)/2

= 4/2 = 2