Question

The solution of the equations x - y = 10 and x + y = 70 is --------.

A) (40,30) B) (30,40) C) (10,60) D) (50,20)​

Answer 1

Answer:

A) 40, 30

Step-by-step explanation:

Adding both equations :-

(x-y= 10). + ( x+y= 70)

2x = 80

x = 40 .

Putting the value of x in any of the equation :-

40-y = 10

-y = 10-40

-y = -30

y = 30

Answer 2

Step-by-step explanation:

x - y = 10 )-----------(1)

x + y = 70 )----------(2)

from equation (1)

we get,

x = 10 + y )---------(3)

putting equation (3) in (2)

• 10 + y + y = 70
• 2y = 60
• y = 30 ( here , we got the value of y )

putting value of y in equation (3)

• x = 10 + 30
• x = 40 ( here, we got the value of x )

Therefore, the solution of the equation is

A) (40,30)