Question

What is the equation of the line in slope-intercept form? the line perpendicular to

y = 1/3x + 5 through (2, 1)

A. y = 1/3x + 7

B. y = -3x + 7

C. y = 3x + 7

D. y = -1/3x + 7

Answer 1

perpendicular has slope tha multiplies to -1
y=mx+b
m=slope
y=1/3x+b
1/3=slope
1/3 times what=-1?
-3 is answer

y=-3x+b
find b
given
(2,1)
(x,y)
x=2 and y=1 is a solution

1=-3(2)+b
1=-6+b
add 6
7=b

y=-3x+7

B is answer