ANSWER
x + y = 4
EXPLANATION
The standard form of a linear equation is given as:
ax + by = c
To do this, we have to find the equation of the line using point-slope method:
y - y1 = m(x - x1)
where (x1, y1) is the point the line passes through
m = slope
The given slope is -1 ad the point the line passes through is (1, 3).
Therefore, we have:
y - 3 = -1(x - 1)
y - 3 = -x + 1
=> x + y = 1 + 3
x + y = 4
That is the equation of the line in standard form.
