Answer:
15.

16. 10 ml of 20% saline and 40 ml of 10% saline
Step-by-step explanation:
A chemist takes x ml of 20% saline and y ml of 10% saline. In total, he takes
x + y ml that is 50 ml, so

There are
ml of salt in x ml of 20% saline and
ml of salt in 10% saline. There are
ml of salt in 50 ml of 12% saline. Thus,

15. We get the system of two equations:

16. Solve this system. From the first equation:

Substitute it into the second equation:

Answer:

Step-by-step explanation:
Since we're looking at perpendicular lines, the slope of the new line is the reciprocal of the original line.
So the slope of our new line is 
So far, we are looking at 
Now we need to find the b value by plugging in the given point.

So the final equation is 
I think that the answer is 15*10^5
It takes 8 liters to cover 800 sqft of floor
there are 3.78541 liters in a gallon so it would take 2.11338 gallons to cover the floor