The equation is y = -1/3x + 2.
Point Slope Form : y - y1 = m(x - x1)
Given: (0,2) and y = 3x + 2
When the line is perpendicular, flip the slope upside down and make it into its opposite ( - to +).
Slope: -1/3
y - 2 = -1/3(x - 0)
y - 2 = -1/3x + 0
+ 2 + 2
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y = -1/3x + 2