Math Problem Statement

Solve the equation: cube root of (x - 10) + cube root of (x - 17) = 3.

Solution

The given equation is:

[ \sqrt[3]{x - 10} + \sqrt[3]{x - 17} = 3 ]

Solution:

  1. Let substitution simplify the problem:
    Let a=x103a = \sqrt[3]{x - 10} and b=x173b = \sqrt[3]{x - 17}.
    From the given equation:
    a+b=3a + b = 3

  2. Relating the terms a3a^3 and b3b^3:
    Since a3=x10a^3 = x - 10 and b3=x17b^3 = x - 17, subtracting gives:
    a3b3=7a^3 - b^3 = 7
    Using the identity a3b3=(ab)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2), we can rewrite this as:
    (ab)((a+b)23ab)=7(a - b)((a + b)^2 - 3ab) = 7
    Substituting a+b=3a + b = 3, we get:
    (ab)(93ab)=7(a - b)(9 - 3ab) = 7

  3. Solving for aa and bb:
    Let ab=ta - b = t. Then, from a+b=3a + b = 3 and ab=ta - b = t, we can express aa and bb as:
    a=3+t2,b=3t2.a = \frac{3 + t}{2}, \quad b = \frac{3 - t}{2}.

    Substitute a=3+t2a = \frac{3 + t}{2} and b=3t2b = \frac{3 - t}{2} into the equations above to

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Math Problem Analysis

Mathematical Concepts

Algebra
Radicals
Cubic Roots
Equations

Formulas

a^3 - b^3 = (a - b)(a^2 + ab + b^2)
a + b = 3
a = (3 + t) / 2, b = (3 - t) / 2

Theorems

Properties of Cube Roots
Difference of Cubes Identity

Suitable Grade Level

Grades 9-12