Answer:
x²+1/x² = 51
Explanation:
Given x - 1/x = 7 ---(1)
We know the algebraic identity:
a²+b²-2ab = (a-b)²
Or
a²+b² = (a-b)²+2ab
Now,
x²+1/x²
= (x-1/x)²+2*x*(1/x)
= (x-1/x)²+2
:7²+2 [ from (1)] =
= 49+2
= 51
Therefore,
x²+1/x² = 51
Answer: 72 minutes
Step-by-step explanation:
Pipe A can empty the water in 180 minutes = (180/60) =3 hours
Pipe A does 1/ 3 of the job in 1 hour.
Pipe B can empty the water in 120 minutes = (120/60) = 2 hours.
Pipe B does 1/ 2 of thejob in 1 hour.
Together they will do:
1/ 3 + 1/ 2 = 5/6
Together, both pipes will do 5/ 6 of the job in one hour.
To get the total time to completely drain the water will be:
= 60 ÷ 5/6
= 60 × 6/5
= 12 × 6
= 72 minutes
It takes 72 minutes to empty the pool.
Answer: plant 1 grows at a faster rate
Step-by-step explanation:
Answer:
65
Step-by-step explanation: