Math Problem Statement

In Exercises 3–10, simplify each expression, if possible.

Solution

Let's go through the simplification of each expression, one by one.

Problem 3

2x23x24x\frac{2x^2}{3x^2 - 4x}

  1. Factor the denominator: 3x24x=x(3x4)3x^2 - 4x = x(3x - 4).
  2. Simplify by canceling xx (if x0x \neq 0): 2x2x(3x4)=2x3x4\frac{2x^2}{x(3x - 4)} = \frac{2x}{3x - 4}

Problem 4

7x3x22x3\frac{7x^3 - x^2}{2x^3}

  1. Factor the numerator: 7x3x2=x2(7x1)7x^3 - x^2 = x^2(7x - 1).
  2. Simplify by canceling x2x^2 (if x0x \neq 0): x2(7x1)2x3=7x12x\frac{x^2(7x - 1)}{2x^3} = \frac{7x - 1}{2x}

Problem 5

x23x18x27x+6\frac{x^2 - 3x - 18}{x^2 - 7x + 6}

  1. Factor both the numerator and denominator:
    • Numerator: x23x18=(x6)(x+3)x^2 - 3x - 18 = (x - 6)(x + 3)
    • Denominator: x27x+6=(x6)(x1)x^2 - 7x + 6 = (x - 6)(x - 1)
  2. Simplify by canceling (x6)(x - 6): (x6)(x+3)(x6)(x1)=x+3x1\frac{(x - 6)(x + 3)}{(x - 6)(x - 1)} = \frac{x + 3}{x - 1}

Problem 6

x2+13x+36x27x+10\frac{x^2 + 13x + 36}{x^2 - 7x + 10}

  1. Factor both the numerator and denominator:
    • Numerator: x2+13x+36=(x+9)(x+4)x^2 + 13x + 36 = (x + 9)(x + 4)
    • Denominator: x27x+10=(x5)(x2)x^2 - 7x + 10 = (x - 5)(x - 2)
  2. Since there are no common factors, the expression remains: (x+9)(x+4)(x5)(x2)\frac{(x + 9)(x + 4)}{(x - 5)(x - 2)}

Problem 7

x2+11x+18x3+8\frac{x^2 + 11x + 18}{x^3 + 8}

  1. Factor the numerator and denominator:
    • Numerator: x2+11x+18=(x+9)(x+2)x^2 + 11x + 18 = (x + 9)(x + 2)
    • Denominator: x3+8=(x+2)(x22x+4)x^3 + 8 = (x + 2)(x^2 - 2x + 4) (sum of cubes)
  2. Simplify by canceling (x+2)(x + 2): (x+9)(x+2)(x+2)(x22x+4)=x+9x22x+4\frac{(x + 9)(x + 2)}{(x + 2)(x^2 - 2x + 4)} = \frac{x + 9}{x^2 - 2x + 4}

Problem 8

x27x+12x327\frac{x^2 - 7x + 12}{x^3 - 27}

  1. Factor both the numerator and denominator:
    • Numerator: x27x+12=(x3)(x4)x^2 - 7x + 12 = (x - 3)(x - 4)
    • Denominator: x327=(x3)(x2+3x+9)x^3 - 27 = (x - 3)(x^2 + 3x + 9) (difference of cubes)
  2. Simplify by canceling (x3)(x - 3): (x3)(x4)(x3)(x2+3x+9)=x4x2+3x+9\frac{(x - 3)(x - 4)}{(x - 3)(x^2 + 3x + 9)} = \frac{x - 4}{x^2 + 3x + 9}

Problem 9

32x4504x312x25x+15\frac{32x^4 - 50}{4x^3 - 12x^2 - 5x + 15}

  1. Factor out common terms where possible:
    • Numerator: 32x450=2(16x425)=2(4x25)(4x2+5)32x^4 - 50 = 2(16x^4 - 25) = 2(4x^2 - 5)(4x^2 + 5)
    • For the denominator, factor by grouping:
      • 4x312x25x+15=4x2(x3)5(x3)=(4x25)(x3)4x^3 - 12x^2 - 5x + 15 = 4x^2(x - 3) - 5(x - 3) = (4x^2 - 5)(x - 3)
  2. The simplified form is: 2(4x25)(4x2+5)(4x25)(x3)=2(4x2+5)x3\frac{2(4x^2 - 5)(4x^2 + 5)}{(4x^2 - 5)(x - 3)} = \frac{2(4x^2 + 5)}{x - 3}

Problem 10

3x33x2+7x727x4147\frac{3x^3 - 3x^2 + 7x - 7}{27x^4 - 147}

  1. Factor out common terms:
    • Numerator: 3x33x2+7x7=3x2(x1)+7(x1)=(3x2+7)(x1)3x^3 - 3x^2 + 7x - 7 = 3x^2(x - 1) + 7(x - 1) = (3x^2 + 7)(x - 1)
    • Denominator: (27x^4 - 147 = 27(x^4 - 5) = 27(x^2 - \sqrt{5})(x^

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Math Problem Analysis

Mathematical Concepts

Algebra
Rational Expressions
Factoring
Simplification

Formulas

Factoring quadratics (ax^2 + bx + c = (px + q)(rx + s))
Sum and difference of cubes (a^3 + b^3 = (a + b)(a^2 - ab + b^2), a^3 - b^3 = (a - b)(a^2 + ab + b^2))
Canceling common factors in rational expressions

Theorems

Factorization theorem
Rational expressions simplification rules

Suitable Grade Level

Grades 9-11