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Zorluk: KolayQuestion Stem Simplification and Target Rephrasing

In Data Sufficiency, simplifying the question target "Is x2<xx^2 < x?" yields the algebraically equivalent question target "Is 0<x<10 < x < 1?" for all real numbers xx.

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The statement is true because solving the inequality x2<xx^2 < x yields the exact range 0<x<10 < x < 1.
Rephrasing the question stem target x2<xx^2 < x algebraically leads directly to x(x1)<0x(x - 1) < 0, which holds true if and only if xx is strictly between 00 and 11. Therefore, the simplified target 'Is 0<x<10 < x < 1?' is completely equivalent.

Adım Adım Çözüm

1
Rearrange the inequality to set one side to zero.
x2x<0x^2 - x < 0
Standard algebraic procedure for solving non-linear inequalities requires comparing a factored expression to zero.
2
Factor the quadratic expression.
x(x1)<0x(x - 1) < 0
Factoring isolates the roots (x=0x = 0 and x=1x = 1) that define the boundary intervals on the real number line.
3
Determine the interval where the product of the factors is negative.
The product is negative between the roots, which corresponds to 0<x<10 < x < 1.
When x<0x < 0, both factors are negative (product is positive). When x>1x > 1, both factors are positive (product is positive). Only when 0<x<10 < x < 1 is xx positive and (x1)(x - 1) negative.

Anahtar Kavram

Simplifying Data Sufficiency question stems by finding equivalent inequality ranges reduces complex targets to direct boundary checks.
Tahmini Süre:45s
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