Step-by-step explanation:
the slope-intercept form is
y = ax + b
"a" being the slope, "b" being the y-intercept (the y-value when x = 0).
to find the slope of the target line we use the slope of the given line : 1/2.
remember, the slope is expressed as ratio (y coordinate change / x coordinate change).
the given line increases the y- value by 1, when the x-value increases by 2.
a perpendicular slope (90°) simply turns y and x upside-down and flips the sign.
so, 1/2 turns into -2/1 = -2.
so, we see our line equation looks like
y = -2x + b
to get b we use the coordinates of the given point :
-2 = -2×1 + b
-2 = -2 + b
0 = b
so thar equation is simply
y = -2x