@dustmaker1000
I am 67 and finally learning some math that I struggled with 50 years ago. Excellent teacher
@ChuckMoore-j3g
I always leave a thumbs-up so I can remember that I've already watched -- BUT often I can't remember what I learned, so I just watch again. Sometimes I wish you would move more quickly through the minutia (like finding LCD in this problem), but I have to be patient and remember that not everyone "sees" the obvious LCD just because I do! Many thanks for your excellent presentations. I am an OLD Elec Engineer so I ought to be clever with math, but I am reminded of a comment made to me by my first Calculus professor, Herr Dr. Broderson at Duke (1964). "Your problem, Mr. Moore, is not with the Calculus; it is with the Arithmetic!" I began doing my homework assignments TWICE and soon realized how correct was his assessment! My "A" in that Calculus class resulted from working step-by-step (as YOU DO!) and not letting the "mental logic" steps take the place of "process." Thanks for all you do!
@ellieangie-buss8585
If you separate the square roots of 5/8 and 8/5 into separate top and bottom roots, then cross multiply and add, you get 5+8 over root(40). That over root 10 gives root 400. So you have 13 over root(400) which is 13/20. Simpler.
@hba12
it can be done mentally (5 + 8) / sqrt (40) ->> 2 sqrt (10) * sqrt (10)
@chrgosselin
Thanks for the fun and instructive videos! What’s the name of the app you’re using?
@alehelawad
multiply top and bottom by √40 (√(5/8x40)+√(8/5x40)) / (√10x√40) (√25+√64)/√400 (5+8)/20 13/20 0.65
@householdufo3357
I miss something at 4:17: square root of 1/16 can be either +1/4 or 1/4: (-1/4) * (-1/4) = 1/16, and sqrt(4/25) = +/ 2/5 So alltogether there are 4 results: -1/4 -2/5 = -0.65 -1/4 + 2/5 = 0.15 1/4 -2/5 = -0.15 1/4 + 2/5 = 0.65
@philippedelaveau528
Put x = sqrt(5/8) then sqrt(10) = 4x and it’s easyjet to simmplify.
@panlomito
V5 / 2V2 x 1 / (V5 . V2) = 1/4 and 2V2 / V5 x 1 / (V5 . V2) = 2/5 so 1/4 + 2/5 = 5/20 + 8/20 = 13/20
@davidniemira
The answer is 13÷20.
@dionysus2006
My XL spreadsheet says 0.65. We have tools, use them
@RyanLewis-Johnson-wq6xs
13/2=6.5 so 13/20=0.65
@Cha.n..dar-888
=13/20// =[(√5√5+√8√8)/√40]/√10 =(5+8)/2√10 .1/√10 =13/2.10= 13/20//
@wolflandmann2299
Unnecessarily complicated. Rationalize denominators! Multiply top and bottom by sqrt(10). You get on top 5/2 + 4 = 13/2, and 10 on the bottom. The result is 13/20 = 0.65.
@MathQueenSusanne