Math Problem Statement

Find a line passing through intersection point of 3x - y -2 =0 and x+2y +1 =0 and -2/3 × m = -1 where m is slope of line.

Solution

We are tasked with finding a line that passes through the intersection point of the lines given by:

  1. 3xy2=03x - y - 2 = 0
  2. x+2y+1=0x + 2y + 1 = 0

And the slope mm of the desired line is given by the equation 23×m=1-\frac{2}{3} \times m = -1.

Step 1: Solve for the intersection point

To find the intersection point of the two lines, we need to solve the system of equations:

3xy2=0(Equation 1)3x - y - 2 = 0 \quad \text{(Equation 1)} x+2y+1=0(Equation 2)x + 2y + 1 = 0 \quad \text{(Equation 2)}

Solve Equation 2 for xx:

x=2y1x = -2y - 1

Substitute this into Equation 1:

3(2y1)y2=03(-2y - 1) - y - 2 = 0

Expand and simplify:

6y3y2=0-6y - 3 - y - 2 = 0 7y5=0-7y - 5 = 0 7y=5-7y = 5 y=57y = -\frac{5}{7}

Substitute y=57y = -\frac{5}{7} back into x=2y1x = -2y - 1:

x=2(57)1=1071=10777=37x = -2\left(-\frac{5}{7}\right) - 1 = \frac{10}{7} - 1 = \frac{10}{7} - \frac{7}{7} = \frac{3}{7}

Thus, the intersection point is (37,57)\left(\frac{3}{7}, -\frac{5}{7}\right).

Step 2: Find the slope mm

We are given the equation:

23×m=1-\frac{2}{3} \times m = -1

Solve for mm:

m=32m = \frac{3}{2}

Step 3: Find the equation of the line

Now, using the point-slope form of the line equation, the line passes through (37,57)\left(\frac{3}{7}, -\frac{5}{7}\right) and has slope m=32m = \frac{3}{2}.

The point-slope form is:

yy1=m(xx1)y - y_1 = m(x - x_1)

Substitute m=32m = \frac{3}{2}, x1=37x_1 = \frac{3}{7}, and y1=57y_1 = -\frac{5}{7}:

y(57)=32(x37)y - \left(-\frac{5}{7}\right) = \frac{3}{2}\left(x - \frac{3}{7}\right)

Simplify:

y+57=32(x37)y + \frac{5}{7} = \frac{3}{2}\left(x - \frac{3}{7}\right)

Multiply out the right-hand side:

y+57=32x914y + \frac{5}{7} = \frac{3}{2}x - \frac{9}{14}

Now subtract 57=1014\frac{5}{7} = \frac{10}{14} from both sides:

y=32x9141014y = \frac{3}{2}x - \frac{9}{14} - \frac{10}{14} y=32x1914y = \frac{3}{2}x - \frac{19}{14}

Thus, the equation of the line is:

y=32x1914y = \frac{3}{2}x - \frac{19}{14}

Summary:

The line passing through the intersection point of the two given lines and having a slope of 32\frac{3}{2} is:

y=32x1914y = \frac{3}{2}x - \frac{19}{14}

Would you like more details, or have any questions about this process?

Follow-up Questions:

  1. How do we solve systems of linear equations graphically?
  2. What is the point-slope form of a line?
  3. How does the slope of a line affect its steepness?
  4. What other methods can be used to find the intersection of two lines?
  5. How do we convert point-slope form to slope-intercept form?

Tip:

Always check your solution by substituting the intersection point into the original line equations to ensure accuracy.

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Math Problem Analysis

Mathematical Concepts

Algebra
Systems of Equations
Slope of a Line
Point-Slope Form

Formulas

Point-Slope form: y - y1 = m(x - x1)
Equation of a line: Ax + By + C = 0
Slope formula: m = (y2 - y1) / (x2 - x1)

Theorems

Solving systems of linear equations

Suitable Grade Level

Grades 9-12