Question 13.
If 3x+2|y|+y=7 and x+|x|+3y=1 , then x+2y is
A
0
B
1
C
D
Question Explanation
Text ExplanationVideo Explanation
We need to check for all regions:
x >= 0, y >= 0
x >= 0, y < 0
x < 0, y >= 0
x < 0, y < 0
However, once we find out the answer for any one of the regions, we do not need to calculate for other regions since the options suggest that there will be a single answer.
Let us start with x >= 0, y >= 0,
3x + 3y = 7
2x + 3y = 1
Hence, x = 6 and y = -11/3
Since y > = 0, this is not satisfying the set of rules.
Next, let us test x >= 0, y < 0,
3x - y = 7
2x + 3y = 1
Hence, y = -1
x = 2.
This satisfies both the conditions. Hence, this is the correct point.
WE need the value of x + 2y
x + 2y = 2 + 2(-1) = 2 - 2 = 0.



