Line A has a slope of 3/2 and passes through the poin (3,3). Line B has a slope of -1/3 and passes through the point (-4,-2). At what point does line A intersect line B?

Respuesta :

Answer:

The point of intersection is (-1,-3)

Step-by-step explanation:

Line A has a slope of 3/2 and passes through the point (3,3)

It is equation is:

[tex]y = \frac{3}{2} (x - 3) + 3[/tex]

Line B has a slope of -1/3 and passes through the point (-4,-2).

It's equation is

[tex]y = - \frac{1}{3} (x + 4) - 2[/tex]

To find their point of intersection, we solve the two equations simultaneously.

Let's equate the right hand sides:

[tex] \frac{3}{2} (x - 3) + 3 = - \frac{1}{3} (x + 4) - 2 \\ \frac{3}{2} (x - 3) + \frac{1}{3} (x + 4) = - 5 \\ 9 (x - 3) + 2 (x + 4) = - 30[/tex]

Expand:

[tex]9x - 27 + 2x + 8 = - 30[/tex]

[tex]11x - 19 = - 30[/tex]

[tex]11x = - 11[/tex]

[tex]x = - 1[/tex]

Put x=-1 in the first equation:

[tex]y = \frac{3}{2} ( - 1 - 3) + 3 = - 6 + 3 = - 3[/tex]

The point of intersection is (-1,-3)

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