Math XL Point slope

Question

Write the equation of a line perpendicular to

8x−9y=−7

that passes through the point

​(−8​,7​).

Answer 1

8x-9y=-7

9y=8x+7

y=8x/9 +7/9 has slope= 8/9 = the coefficient of the x term when the linear equation is solved for y

perpendicular"s slope

= the negative inverse of 8/9 = -9/8

y=-9x/8 +b

through (-8,7)

plug in the point to find b, x=-8, y=7

7=-9(-8)/8 +b

b=7-9=-2

y=-9x/8 -2