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Zorluk: OrtaEquivalent Algebraic Expressions

For all x>1x > 1, which of the following is equivalent to the expression 2x25x32x+1(x4)\frac{2x^2 - 5x - 3}{2x + 1} - (x - 4)?

  1. A
    -7
  2. B
    2x - 7
  3. 1Cevap
  4. D
    7

Cevap

1
The correct answer is 11. Factoring the numerator of the rational expression gives 2x25x3=(2x+1)(x3)2x^2 - 5x - 3 = (2x + 1)(x - 3). Since x>1x > 1, the denominator 2x+12x + 1 is non-zero, allowing the expression to be simplified to x3x - 3. Subtracting (x4)(x - 4) and distributing the negative sign to both terms inside the parentheses yields (x3)(x4)=x3x+4=1(x - 3) - (x - 4) = x - 3 - x + 4 = 1.

Adım Adım Çözüm

1
Factor the quadratic expression in the numerator of the rational term.
2x25x3=(2x+1)(x3)2x^2 - 5x - 3 = (2x + 1)(x - 3)
This allows for the identification of common factors that can be simplified with the denominator.
2
Simplify the rational expression by canceling the common factor in the numerator and denominator.
(2x+1)(x3)2x+1=x3\frac{(2x + 1)(x - 3)}{2x + 1} = x - 3
Since x>1x > 1, the term 2x+12x + 1 is positive and non-zero, making the division valid.
3
Subtract the linear expression from the simplified rational expression, distributing the negative sign to both terms inside the parentheses.
(x3)(x4)=x3x+4=1(x - 3) - (x - 4) = x - 3 - x + 4 = 1
This performs the final subtraction and simplifies the expression to its equivalent constant form.

Anahtar Kavram

Simplifying rational expressions by factoring and performing operations on equivalent expressions
Tahmini Süre:1m 15s
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