( x × 4 x 3 ) x ! x ! = ⎝ ⎛ ( i 2 ) x ! x ! ⎠ ⎞ x − 8 8 2 0
Find the real value of x satisfying the real equation above.
Note :- Here x ∈ { − 1 , 0 , 1 } .
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i 2 = − 1 = 1
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Oh yeah thanks, but answer remains same as explained above.
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nice Solution+Question .. +1
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@Sabhrant Sachan – The reason I post these exponent questions is because of wncouragement of people like you :)
@Sabhrant Sachan – Jeez, Thanks!
wait... How did you get x 4 × x 3 = x 4 7
x 4 × x 3 ⟹ x 4 × x 2 3 ⟹ x 4 + 2 3 ⟹ x 2 1 1
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@Sabhrant Sachan – It is x × 4 x 3 wait I qill clear it up in a jiffy.
You should mention in the question that x is positive Natural Number because for x = 1/2, (-1)^x! becomes a number other than 1.
May I ask for some tips on how do you know that 7 ! = 5 0 4 0 without using calculator? Or is it impossible? Teehee. 😅
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if you practice enough questions, you will remember factorial of numbers till 8 or 10
I have remembered factprials upto 10 XD
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Wow... impressive XD
Why dont you update your score in my set :) You have solved this correctly (+1)
Factorize 5040.
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( x × 4 x 3 ) x ! x ! x 4 7 x ! x ! x ! x 4 7 x ! 1 x ! x − 4 7 x ! Equating the powers, we get : − x − 4 7 x ! Equating the powers, we get : − − 4 7 x ! x ! x ! x ! x = ⎝ ⎛ ( i 2 ) x ! x ! ⎠ ⎞ x − 8 8 2 0 = ( − 1 x ! x ! ) x − 8 8 2 0 = x ! x − 8 8 2 0 = x ! x − 8 8 2 0 = x − 8 8 2 0 = − 8 8 2 0 = 7 8 8 2 0 × 4 = 5 0 4 0 = 7 × 6 × 5 × 4 × 3 × 2 × 1 = 7
In step 2, i x ! = 1 , because x! is even for all x ∈ { − 1 , 0 , 1 } because they are multiple of 2 .