ANSWER
D
Step-by-step explanation:
d=√((x_2-x_1)²+(y_2-y_1)²)
Remark
The proof is only true if m and n are equal. Make it more general.
m = 2k
n = 2v
m + n = 2k + 2v = 2(k + v).
k and v can be equal but many times they are not. From that simple equation you cannot do anything for sure but divide by 2.
There are 4 combinations
m is divisible by 4 and n is not. The result will not be divisible by 4.
m is not divisible by 4 but n is. The result will not be divisible by 4.
But are divisible by 4 then the sum will be as well. Here's the really odd result
If both are even and not divisible by 4 then their sum is divisible by 4
I think it’s the bottom one
Answer:
1.49 hrs or 1 hr and 30 minutes approximately
Step-by-step explanation:
if fran go 2.8m up then the river flow at a rate of 0.8m; the since we are taking the speed of fran and river to be constant. the ratio between their speed will always remain constant. that is if 0.8/2.8 = 0.286≈ this will be always constant.
so if he go up 4m then the horizontal length has to be 1.143 because 1.143/4 = 0.286.
now we find the distance between frans initial positon and final position. to find it we use pythagoras theorem.

to find the time divide distance traveled by speed;
4.160/2.8 = 1.49 hrs