Math Problem Statement

Find the x-intercept of the line from the given table of points.

Solution

To find the xx-intercept of the line from the given table of points, we need to follow these steps:

  1. Determine the slope (mm) of the line: The formula for slope is: m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1} Let's use two points, (38,40)(-38, 40) and (23,30)(-23, 30): m=304023(38)=1015=23.m = \frac{30 - 40}{-23 - (-38)} = \frac{-10}{15} = -\frac{2}{3}.

  2. Find the equation of the line: The slope-intercept form of a line is: y=mx+by = mx + b Substitute one point, say (38,40)(-38, 40), and m=23m = -\frac{2}{3} to solve for bb (the yy-intercept): 40=23(38)+b.40 = -\frac{2}{3}(-38) + b. Simplify: 40=763+b.40 = \frac{76}{3} + b. Subtract 763\frac{76}{3} from 40: b=40763=1203763=443.b = 40 - \frac{76}{3} = \frac{120}{3} - \frac{76}{3} = \frac{44}{3}. So the equation of the line is: y=23x+443.y = -\frac{2}{3}x + \frac{44}{3}.

  3. Find the xx-intercept: At the xx-intercept, y=0y = 0. Substitute y=0y = 0 into the equation: 0=23x+443.0 = -\frac{2}{3}x + \frac{44}{3}. Solve for xx: 23x=443.\frac{2}{3}x = \frac{44}{3}. Multiply through by 3: 2x=44.2x = 44. Divide by 2: x=22.x = 22.

Final Answer:

The xx-intercept of the line is x=22x = 22.


Would you like a detailed explanation of any step?

Related Questions:

  1. How can we derive the slope-intercept equation from two points on a line?
  2. What is the significance of the xx-intercept in real-world problems?
  3. How do we calculate the yy-intercept directly from two points?
  4. What changes in the process if the line is vertical or horizontal?
  5. How does the slope of a line affect its graphical representation?

Tip:

Always double-check your slope calculations when finding intercepts—small errors can lead to incorrect results!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Equations
Slope-Intercept Form
Intercepts

Formulas

Slope formula: m = (y2 - y1) / (x2 - x1)
Slope-Intercept Form: y = mx + b

Theorems

Equation of a line from two points
Finding the x-intercept by setting y = 0

Suitable Grade Level

Grades 8-10