Answer:
Below.
Step-by-step explanation:
These are perpendicular line which intersect at (-4, -9).
Vertical line is x = -4.
Horizontal lone is y = -9.
120/4=30. Remember its widthxlength. if you forget ask your teacher or look online for more help. Good luck.
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.
the simplified so 9 and 18 can both be divided by 9 so 9/18 dived by 9/9 would be 1/2 you can also but 9 divided by 18 in a calculator