Question

(-1, 3) and perpendicular to y = -one thirdx + 7.

y = 3x - 12

y = 3x + 6

y = 3x - 6

y = 3x

Answer 1

y = -1/3x + 7

do you know what the slope is in this equation ?

Answer 2

y = mx + b...the slope is in the m position. Therefore, the slope of this equation is -1/3. However, we are looking for a line perpendicular, so we need to find the negative reciprocal of the slope in the equation. All that means is you " flip " the slope and change the sign. So, the slope we need is the negative reciprocal of -1/3, which is 3/1 or just 3.

Understand so far ?

Answer 3

now we will use point slope form...y - y1 = m(x - x1)
slope(m) = 3
(-1,3) x1 = -1 and y1 = 3

now lets sub our info into the formula
y - 3 = 3(x - (-1)
y - 3 = 3(x + 1)
y - 3 = 3x + 3
y = 3x + 3 + 3
y = 3x + 6 <-- your answer

any questions just ask :)