Math Quiz and Solver: square

Showing posts with label square. Show all posts

Showing posts with label square. Show all posts

Sunday, September 25, 2016

The Solution of Two Square plus Two Minus Square

Problem
Jika 2^x+2^-x=5, berapakah nilai 2^2x+2^-2x=...

Solution

2^x+2^-x	=	5
[2^x+2^-x]²	=	5²	make it square
[2^x+2^-x].[2^x+2^-x]	=	5²
2^x.2^x+2^x.2^-x+2^-x.2^x+2^-x.2^-x	=	25
2^2x+2.2^x.2^-x+2^-2x	=	25
2^2x+2.2^x+(-x)+2^-2x	=	25
2^2x+2.2⁰+2^-2x	=	25
2^2x+2.1+2^-2x	=	25
2^2x+2+2^-2x	=	25
2^2x+2^-2x	=	25-2
2^2x+2^-2x	=	23

So the solution is 2^2x+2^-2x=23

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