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Which of the following statements is true about lines 3y + 2x - 9 = 0 and 12y + 8x - 5 = 0? They are parallel They are perpendicular They are parallel to the x-axis They are parallel to the y-axis

Respuesta :

i think c is the answer

Answer:

The statement "They are parallel" is true.

Step-by-step explanation:

The general form of the equation of a straight line is:

[tex]Ax+By+C=0[/tex]

where A, B, and C are three real numbers.

A line parallel to the x-axis has this form [tex]y=C[/tex] where C is a real number.

A line parallel to the y-axis has this form [tex]x=C[/tex] where C is a real number.

From the lines given none of these have the form of a line parallel to the x-axis or the y-axis. Therefore the statements "They are parallel to the x-axis" and "They are parallel to the y-axis" are false.

Two non-vertical lines in a plane are parallel if they have both:

  • the same slope
  • different y-intercepts

Two non-vertical lines are perpendicular if the slope of one is the negative reciprocal of the slope of the other.

To check if the lines are parallel of perpendicular you must transform these lines into the slope/intercept form

[tex]y=mx+b[/tex]

where m represents the slope and b represents the y-intercept.

The slope/intercept form for the first line is:

[tex]3y+2x-9=0\\\\3y+2x-9-2x=0-2x\\\\3y-9=-2x\\\\3y-9+9=-2x+9\\\\3y=-2x+9\\\\y=\frac{-2x+9}{3}\\\\y=\frac{-2}{3}x+3[/tex]

The slope/intercept form for the second line is:

[tex]12y+8x-5=0\\\\12y+8x-5-8x=0-8x\\\\12y-5=-8x\\\\12y-5+5=-8x+5\\\\12y=-8x+5\\\\y=\frac{-8x+5}{12}\\\\y=\frac{-2}{3}x+\frac{5}{12}[/tex]

We can see that the lines have the same slope and different y-intercepts. Therefore the statement "They are parallel" is true.

We can check our work with the graph of the lines.

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