Question

problem ...need to be solved with real theories

Answer 1

\[-20=20\]
\[16-36=25-45\]
\[4^{2}-4\times{9 } =5^{2}-5\times{ 9 }\]
\[4^{2}-2\times4\times\frac{9 }{ 2 }=5^{2}-2\times5\frac{ 9 }{ 2}\]
\[4^{2}-2\times4\times\frac{9 }{ 2 }+\left( \frac{ 9 }{ 2 } \right)^{2}=5^{2}-2\times5\frac{ 9 }{ 2}+\left( \frac{ 9 }{ 2 } \right)^{2}\]
\[\left( 4-\frac{ 9 }{ 2 } \right)^{2}=\left( 5-\frac{ 9}{ 2 } \right)^{2}\]
\[\sqrt{\left( 4-\frac{ 9 }{ 2 } \right)^{2}}=\sqrt{\left( 5-\frac{ 9}{ 2 } \right)^{2}}\]
\[4-\frac{ 9 }{ 2 }=5-\frac{ 9 }{ 2 }\]

Answer 2

how can I edit ?
−20=-20 m sory it meant like this both negative

Answer 3

what level math is this?

Answer 4

the high level I mean numbers on R

Answer 5

hmm...
what definition of real number you use? Dedekind partitions maybe?

Answer 6

a made up confusion
I am not sure the wrong step .
but is 4 double of -2,2 in all condition accept geyometrical calculations
when we take off the root square with absolute value ?

Answer 7

square root taking is like finding side of square who's diagonal is equal to the number under root sign

Answer 8

but still the result is not equal even if both are negative

Answer 9

length can never be negative

Answer 10

I think that's what is ment by geometrical calculations

Answer 11

it appears that:
\[\pm (4 - \frac{ 9 }{ 2 }) = ∓(5-\frac{ 9 }{ 2 })\]

Answer 12

yes exactelly but why ? mean wich step is wrong and how ..

Answer 13

\(\sqrt{x^2}= |x|\) actually

Answer 14

so, if x is negative, as is the case for 4-9/2
|x| will be -x
= - (4-9/2) = 1/2

for 5-9/2, x is positive so |x| =x
so, 5-9/2 = 1/2

Answer 15

got this ?

Answer 16

because answer of square root can never be negative while dealing with real numbers

Answer 17

it's been a long time for me since i studied those. one more thing i there like a theorical proof ? texts ...
and thanks seems obviously right

Answer 18

theoritical proof...if i find one i will attach...