Math Problem Statement

Solve the following equation by making an appropriate substitution.

4 x minus 13 x Superscript 1 divided by 2 Baseline plus 10 equals 0

Solution

The equation is:

4x13x12+10=04x - 13x^{\frac{1}{2}} + 10 = 0

Step 1: Substitution

Let u=x12u = x^{\frac{1}{2}}, or equivalently, u2=xu^2 = x.

Substituting this into the equation, we replace x12x^{\frac{1}{2}} with uu and xx with u2u^2. The equation becomes:

4u213u+10=04u^2 - 13u + 10 = 0

Step 2: Solve the quadratic equation

Now solve the quadratic equation 4u213u+10=04u^2 - 13u + 10 = 0.

We can use the quadratic formula:

u=(13)±(13)24(4)(10)2(4)u = \frac{-(-13) \pm \sqrt{(-13)^2 - 4(4)(10)}}{2(4)}

Simplifying the discriminant:

u=13±1691608u = \frac{13 \pm \sqrt{169 - 160}}{8}

u=13±98u = \frac{13 \pm \sqrt{9}}{8}

u=13±38u = \frac{13 \pm 3}{8}

This gives two solutions for uu:

u=13+38=168=2u = \frac{13 + 3}{8} = \frac{16}{8} = 2 u=1338=108=54u = \frac{13 - 3}{8} = \frac{10}{8} = \frac{5}{4}

Step 3: Back-substitute for uu

Recall that u=x12u = x^{\frac{1}{2}}, so:

  • If u=2u = 2, then x12=2x^{\frac{1}{2}} = 2, which means x=22=4x = 2^2 = 4.
  • If u=54u = \frac{5}{4}, then x12=54x^{\frac{1}{2}} = \frac{5}{4}, which means x=(54)2=2516x = \left( \frac{5}{4} \right)^2 = \frac{25}{16}.

Final Answer:

The solutions to the equation are: x=4orx=2516x = 4 \quad \text{or} \quad x = \frac{25}{16}

Would you like further details on any part of this solution?

Related Questions:

  1. How do you solve a general quadratic equation using substitution?
  2. What is the process for finding the square root of a fraction?
  3. Can this method be applied to solve higher-degree polynomials?
  4. What is the importance of checking solutions after substitution?
  5. How can you confirm if a quadratic equation is factorable?

Tip: When using substitutions in equations, always remember to convert back to the original variable at the end!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Substitution
Quadratic Equations

Formulas

Quadratic equation formula: ax^2 + bx + c = 0
Substitution: u = x^(1/2)
Quadratic formula: u = [-b ± √(b^2 - 4ac)] / 2a

Theorems

Quadratic formula

Suitable Grade Level

Grades 9-12