Referring to the xy-plane above, if the scales on both axes are the same, which of the following could be the equation of line P ?
General equation of a straight line in xy plane is
y=mx + cwhere m=slope of line and c=intercept of line
Since no co-ordinate of line P is given in question so our aim is to get a general equation of
line P and match it with given options.
Now, c=intercept of line
Intercept is when x=0 what is value of y.
from the diagram we can see that x=0 at y-axis and it is negative
so
intercept (c) is negative.Also, m=slope of line
slope of line is positive when ---> x increases, then y also increases and vice versa
slope of line is negative when ---> x increases, then y decreases.
From diagram, we can see that line P is intersecting at x-axis and y-axis
we can assume point on x-axis as P1(-x,0) and at y-axis as P2(0,-y)
Now when line P goes from P1 to P2 i.e x co-ordinate is changing from -x to 0 so x co-ordinate is increasing.
And when line P goes from P1 to P2 i.e y co-ordinate is changing from 0 to -y so y co-ordinate is decreasing.
From this we can say that
slope of line(m) is negative.From this, we can conclude that
general equation of line P can be
y=\(-mx - c\)Among the options, only E matches the general equation of line P
Hence,
E