Option: c is the correct answer.
The value of x is 10.
We know that a solution of the system of linear equation can be obtained by the method of substitution.
Here we are given a system of equations as:
x-y=11-------(1)
and 2x+y=19------(2)
We will get the value of y in terms of x from equation(1) and put that value in equation (2) to obtain the value of x as:
y=x-11
Now putting in equation (2)
2x+x-11=19
⇒ 3x-11=19
⇒ 3x=19+11
⇒ 3x=30
⇒ x=10
( since on dividing both side by 3)
Hence, the value of x is:
10