Answer: 
Step-by-step explanation:
1. By definition, you have if
, then 
2. Keeping this on mind, you must follow the proccedure shown below:
- You have that:

Where:

- Substitute values into
. Then, you obtain:
Answer:
It will take 6 hours for the new pump to drain the pool.
Step-by-step explanation:
As the complete question is not given, the complete question is found online and is attached herewith
Let the rate of new pump is given as x=W/t_1
Let the rate of the old pump is given as y=W/t_2
it is given that the time t_2=2t_1
So by substituting the values of t_2 in the rate equation of y
y=W/2t_1
y=(W/t_1*2)=x/2
Also the total rate of both the pumps is given as W/t3 where t3 is given as 4 hours so the equation becomes
x+y=W/4
x+x/2=W/4
3x/2=W/4
As x=W/t_1
3W/2t_1=W/4
Now as W is same on both sides so
3/2t_1=1/4
12=2t_1
t_1=6 hours
So it will take 6 hours for the new pump to drain the pool.
side angel side inequality
Answer:
B
Step-by-step explanation:
The result is
9
a
2
−
16
The reason is the following:
The problem is an example of a notable product: "the sum multiplied by the diference is equal to the difference of squares", that is to say:
(
a
+
b
)
⋅
(
a
−
b
)
=
a
2
−
b
2
.
By applying this to our question, we obtain that:
(
3
a
−
4
)
⋅
(
3
a
+
4
)
=
(
3
a
)
2
−
(
4
)
2
=
9
a
2
−
16
.