The length of a table, the width of a classroom, and the length of a car can be easily measured without using trigonometry (could probably use a meter stick or measuring tape) because we can easily reach both ends
the width of a wide river is a little different, it may not be practical to measure the distance across directly.
Multiply the first equation by 2:
4x+10y=8
Subtract the second equation from this so the 4x cancels:
3y = -3
y = -1
Plug into first equation:
2x -5 = 4
2x = 9
x = 9/2 = 4 1/2 = 4.5
So (x,y) = (-1,4.5)
No it is missing 10 yards in length