Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
To simplify
![\sqrt[4]{\dfrac{24x^6y}{128x^4y^5}}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B%5Cdfrac%7B24x%5E6y%7D%7B128x%5E4y%5E5%7D%7D)
we need to use the fact that
![\sqrt[4]{x^4}=|x|](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7Bx%5E4%7D%3D%7Cx%7C)
Why the absolute value? It's because 
.
We start by rewriting as
![\sqrt[4]{\dfrac{2^23x^6y}{2^6x^4y^5}}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B%5Cdfrac%7B2%5E23x%5E6y%7D%7B2%5E6x%5E4y%5E5%7D%7D)
![\sqrt[4]{\dfrac{2^23x^4x^2y}{2^42^2x^4y^4y}}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B%5Cdfrac%7B2%5E23x%5E4x%5E2y%7D%7B2%5E42%5E2x%5E4y%5E4y%7D%7D)
Since 
, we have 
, and the above reduces to
![\sqrt[4]{\dfrac{3x^2y}{2^4y^4y}}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B%5Cdfrac%7B3x%5E2y%7D%7B2%5E4y%5E4y%7D%7D)
Then we pull out any 4th powers under the radical, and simplify everything we can:
![\dfrac1{\sqrt[4]{2^4y^4}}\sqrt[4]{\dfrac{3x^2y}{y}}](https://tex.z-dn.net/?f=%5Cdfrac1%7B%5Csqrt%5B4%5D%7B2%5E4y%5E4%7D%7D%5Csqrt%5B4%5D%7B%5Cdfrac%7B3x%5E2y%7D%7By%7D%7D)
![\dfrac1{|2y|}\sqrt[4]{3x^2}](https://tex.z-dn.net/?f=%5Cdfrac1%7B%7C2y%7C%7D%5Csqrt%5B4%5D%7B3x%5E2%7D)
where 
allows us to write 
, and this also means that 
. So we end up with
![\dfrac{\sqrt[4]{3x^2}}{2y}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Csqrt%5B4%5D%7B3x%5E2%7D%7D%7B2y%7D)
making the last option the correct answer.
Y= x^2
Are you trying to graph the problem to??
D) 35
Use the slope formula
(y2-y1)
______
(x2-x1)
(70-35)
______= 35/1
(1 - 0)
<span>58%
The sum of all the probabilities has to be 100%. In tennis, because there's no time limit, a match will always result in a win or a loss. Since Garry has won 42% of his games, that means that he's lost 100% - 42% = 58% of his games. And if you assume his win/loss ratio is reflective of his future games as well as his past games, then he as a 58% chances of loosing his next match.</span>
