Answer:
Point just took the test and this is the answer.
Step-by-step explanation:
X-3y=6
x+y=2
this is an substitution problem
so first you can do is rewrite the problem by subjection one variable
x=3y+6
then substitute this in the other proble
x+y=2
(3y+6)+y=2
4y+6=2
4y=2-6
4y=-4
y=-1
then substitute the no. in the original equation.
x=3y+6
x=3(-1)+6
x=-3+6
x=3
now you got the intercepts and you draw the line and check.
it's in the IV quadrant
X = 20
First, you move the 40 to the other side.
-2x=-40
Then, you divided -40 by -2.
x= -40/-2
x= 20
x is 20 because the negatives cancel out making it positive.
Answer:
The value is 
Step-by-step explanation:
From the question we are told that
The mean is 
The standard deviation is 
The safest water level is between 7.2 and 7.8
Generally the probability that the selected pool has a pH level that is not considered safe is mathematically represented as

Here

Generally 
So
=>
From the z-table the probability of (Z < -1.5) and ( Z <1.5) are

and

So
So

=> 