Answer:
5x-8y
Step-by-step explanation:
4x-9y+x+y
=4x+-9y+x+y
=4x+-9y+x+y
=(4x+x)+(-9y+y)
=5x+-8y
=5x-8y
Answer:
y=(1/3)x- 4/3
Step-by-step explanation:
If two lines are perpendicular to each other, then the slopes will be the negative inverse to each other.
Example:
the negative inverse of 2 is -1/2
the slope of
is -3
the negative inverse of -3 is 
So we have the perpendicular line be :
Since it also go through (4,0)
plug in we get 

So the equation would be

Answer:
$30
Step-by-step explanation:
If it's 25% off, then to find the sale price we just need to subtract 25% of the original price from the original price.
Original price is 40 so we do 40 - (40 * 0.25) = 30