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.
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