Question

Write an equation of the line that passes through (1, −1) and is perpendicular to the line y=1/2x−3. An equation of the perpendicular line is y=

Answer 1

We know that a line is perpendicular to another line if one slope is the opposite reciprocal  of the other. So, the slope of the line perpendicular to y=1/2x-3 would by -2/1 or -2. Now, to find the y intercept, plug in the coordinate (1, -1) to the equation y = -2x + b. 

-1 = -2(1) + b
 
-1 = -2 + b

1 = b

Now we know the y intercept and slope of the new line, which is enough to make the equation. y = -2x + 1 is your answer. 

Hope this helps!! :)

Answer 2

Y = 1/2x - 3. Slope here is 1/2. A perpendicular line will have a negative reciprocal slope. All that means is flip the slope and change the sign. So the perpendicular line will have a slope of -2.

y = mx + b
slope(m) = -2
(1,-1)...x = 1 and y = -1
now we sub and find b, the y int
-1 = -2(1) + b
-1 = -2 + b
-1 + 2 = b
1 = b

so ur perpendicular equation is : y = -2x + 1