If you can find your way through all the smoke of the definition,
you find that an increase of 10 times the intensity is an increase
of 10 dB.
Next, if you can find your way over, under, around, and through
all the speeds and distances of the vehicles, you'll find that you
don't need them. Right in the middle of the pile, it says "intensity
10 times that of ...". That right there tells you that the sound of
the truck is 10 dB louder than the sound of the car.
So the car is 70 dB (asked for, and then given), and the truck is 80 dB.
First find the slope
the slope of the line that passes through (x1,y1) and (x2,y2) is
(y2-y1)/(x2-x1)
given
(-4,3) and (6,-2)
the slope is (-2-3)/(6-(-4))=(-5)/(6+4)=-5/10=-1/2
so
the equation of a line tat passes through the point (x1,y1) and has a slope of m is
y-y1=m(x-x1)
use (-4,3)
and we found slope=-1/2
y-3=-1/2(x-(-4))
y-3=-1/2(x+4)
if yo want slope intercept form
y-3=-1/2x-2
y=-1/2x+1
if yo want standard form
1/2x+y=1
x+2y=2
