Can you please attach the photo?
A leg of a right triangle can never be greater then the hypotenuse
this formula will tell you if it's a valid right triangle

the first two question marks are the legs of the triangle while the one after the = is the hypotenuse.
THE STEPS:




ANSWER:
Answer:

Step-by-step explanation:
We are given:

![interval = [a,b] = [0,2]](https://tex.z-dn.net/?f=interval%20%3D%20%5Ba%2Cb%5D%20%3D%20%5B0%2C2%5D)
Since
⇒ 
Riemann sum is area under the function given. And it is asked to find Riemann sum for the left endpoint.

Note:
If it will be asked to find right endpoint too,

The average of left and right endpoint Riemann sums will give approximate result of the area under
and it can be compared with the result of integral of the same function in the interval given.
So, 

Result are close but not same, since one is approximate and one is exact; however, by increasing sample rates (subintervals), closer result to the exact value can be found.
Since 4x/5 is the reciprocal of 1/20, that means that 4x/5 = 20/1, or 20. Using this info, we can form the equation
. From there we can solve for x.
Firstly, multiply both sides by 5: 
Next, divide both sides by 4 and your answer will be 