Question

11. If x = a, y = b is the solution of the equations x – y = 2 and x + y = 4, then the values

of a and b are, respectively

(A) 3 and 5 (B) 5 and 3

(C) 3 and 1 (D) –1 and –3​

Answer 1

Answer:

(C) 3 and 1

Step-by-step explanation:

Given, x=a and y=b.

Given equations, x-y=2( assume it as equation 1)

x+y=4( assume it as equation 2)

Equation 1+2,

x-y=2

x+y=4

- - - - - - -

2x=6( y gets cancelled as there is a negative y and a positive y implies y-y=0)

x=6/2

x=3

But x=a implies a=3

substitute a in equation 1 (it can be substituted even in equation 2)

x-y=2

3-y=2

y=3-2

y=1

But y=b implies b=1

Therefore, a=3 and b=1

Answer 2

Answer:

(c) 3 and 1

Step-by-step explanation:

a - b = 2 ( 1 )

+

a +b = 4 ( 2 )

-------------

2a. = 6

a = 6/2

a = 3

from equation ( 1 )

a - b = 2

3 - b = 2

3 - 2 = b

1 = b

b = 1