Explanation:
Hey there!!
To solve this type of question, use these steps.
- Find these 1st equation by using one point formula of point.
- After this from equation 2 find slope, by comparing it with y= mx + c if it is in slope intercept form.
- Then, as per the conditions of parallel lines, use m1=m2, then put the value of m1 in equation 1st.
- Then simplify them.
So, let's work with these steps.
Now,
The equation of a st.line passing through point (2,1) is,

Put all values.

It is the 1st equation.
Another equation is,
y = -2x -3.......(ii)
Comparing the equation with y = mx+c.
Therefore, from equation (ii)
m2 = -2
Now, as per condition of parallel lines,
m1=m2= -2
Putting the value of m1 in equation 1st.

y - 1 = -2x + 4
y = -2x +5.
Therefore, the equation is y = -2x +5.
Hope it helps...