Math Problem Statement

Find the value of x and the angles ABD and DBC if (2x + 23)° and (9x - 5)° form a straight line.

Solution

The image shows an angle diagram with three labeled points: AA, BB, and CC, where two angles are given:

  • Angle ABD=(2x+23)\angle ABD = (2x + 23)^\circ
  • Angle DBC=(9x5)\angle DBC = (9x - 5)^\circ

Since the two angles ABD\angle ABD and DBC\angle DBC form a straight line (which equals 180°), we can write the equation:

(2x+23)+(9x5)=180(2x + 23) + (9x - 5) = 180

Let's solve for xx.

Step-by-step Solution:

  1. Combine like terms: (2x+9x)+(235)=180(2x + 9x) + (23 - 5) = 180 11x+18=18011x + 18 = 180

  2. Subtract 18 from both sides: 11x=16211x = 162

  3. Solve for xx by dividing both sides by 11: x=1621114.73x = \frac{162}{11} \approx 14.73

Thus, x14.73x \approx 14.73.

Now, let's find the angles:

  1. ABD=2x+23=2(14.73)+23=29.46+23=52.46\angle ABD = 2x + 23 = 2(14.73) + 23 = 29.46 + 23 = 52.46^\circ
  2. DBC=9x5=9(14.73)5=132.575=127.57\angle DBC = 9x - 5 = 9(14.73) - 5 = 132.57 - 5 = 127.57^\circ

Check:

52.46+127.57=18052.46^\circ + 127.57^\circ = 180^\circ

So, the solution is consistent.

Would you like more details on the process? Here are some related questions:

  1. What if the angles didn't form a straight line?
  2. Can you explain angle relationships in a triangle?
  3. How can I verify the consistency of solutions in geometry problems?
  4. What are the applications of this angle relationship concept?
  5. How does the straight angle property help solve equations?

Tip: Always double-check the sum of your angles in geometry problems to ensure they meet the required condition (e.g., straight line = 180°, triangle = 180°, etc.).

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Math Problem Analysis

Mathematical Concepts

Algebra
Geometry
Linear Pair of Angles

Formulas

(2x + 23) + (9x - 5) = 180
x = 162 / 11

Theorems

Linear Pair Theorem

Suitable Grade Level

Grades 8-10