What is the y-intercept of the equation of the line that is perpendicular to the line y = 3/5x + 10 and passes through the point (15, –5)?

So
perpendicular lines have slope that multiply to -1

y=mx+b
m=sloe

given
y=3/5x+10
slope is 3/5

perpendicular
3/5 times what=-1?
times both sides by 5/3
what=-5/3
the other slope is -5/3

y=-5/3x+b
find b which is the y intercept
passes through (15,-5)
input that (x,y) so x=15 and y=-5 is a point

-5=(-5/3)(15)+b
-5=-25+b
20=b
the y intercept is 20