Animated Solution for Mathematics - Basic Mathematics: Solve for x:4x−3x−1/2=3x+1/2−22x−1
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Visualized Solution
The Given Equation
Given equation: 4x−3x−21=3x+21−22x−1
Identify the bases: Base 4 (and 2) and Base 3.
Grouping Similar Bases
Rearrange terms to group similar bases:
4x+22x−1=3x+21+3x−21
Simplifying Exponents
Apply exponent rules: am−n=anam and am+n=am⋅an
Left Side: 22x−1=2(22)x=24x
Right Side: 3x+21=3x⋅3 and 3x−21=33x
Equation becomes: 4x+24x=3x⋅3+33x
Factoring 4x and 3x
Factor out the exponential terms:
4x(1+21)=3x(3+31)
Calculating Constants
Simplify the terms in brackets:
Left: 1+21=23
Right: 3+31=3(3)2+1=33+1=34
Equation: 23⋅4x=34⋅3x
Isolating the Ratio (34)x
Isolate x terms on the left and constants on the right:
3x4x=34⋅32
(34)x=338
Matching the Bases
Express the Right Hand Side as a power of 34:
338=(3)323=(32)3
Since 32=34=(34)21
Then (32)3=((34)21)3=(34)23
Final Answer
Equate the exponents since the bases are the same:
(34)x=(34)23
Therefore, x=23=1.5
Key Takeaway: Grouping terms with similar bases and using exponent properties are essential for solving exponential equations.
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The Sigma Insight: Theory of Indices
Analyzing the Setup
Imagine you are standing before a complex exponential equation: 4x−3x−1/2=3x+1/2−22x−1. At first glance, it looks like a chaotic jumble of bases and fractional exponents.
In the world of JEE Advanced, chaos is just order waiting to be discovered. The secret to mastering these problems is to stop seeing a single equation and start seeing 'families'.
We have a base-2 family (4x and 22x−1) and a base-3 family (3x+1/2 and 3x−1/2). By moving the negative terms to their respective sides, we transform the equation into:
4x+22x−1=3x+1/2+3x−1/2
The Power of Indices
Now, we must confront the fractional exponents. Recall the fundamental law of indices: am−n=anam.
For the base-2 family, the term 22x−1 is simply 222x. Since 22x is (22)x, which is 4x, our term becomes 24x.
Similarly, for the base-3 family, 3x+1/2 becomes 3x⋅3, and 3x−1/2 becomes 33x. Substituting these back, our equation becomes:
4x+24x=3x⋅3+33x
The Art of Factoring
We are now at the most satisfying part of the process: the extraction. Notice that both sides now have a common exponential term.
On the left, we factor out 4x to get 4x(1+21), which simplifies to 4x(23). On the right, we factor out 3x to get 3x(3+31).
Simplifying the bracket on the right, we find 3+31=33+1=34. Now, we have:
23⋅4x=34⋅3x
The Final Convergence
To solve for x, we isolate the variable by dividing both sides by 3x and multiplying by the reciprocal of the constant on the left. This yields:
(34)x=34⋅32=338
The final hurdle is to express the right side as a power of 34. Since 338=(32)3 and 32=(34)1/2, the right side is simply:
((34)1/2)3=(34)3/2
Equating the exponents, we arrive at the final result: