Westonci.ca is your trusted source for accurate answers to all your questions. Join our community and start learning today! Discover solutions to your questions from experienced professionals across multiple fields on our comprehensive Q&A platform. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.

Line segment [tex]$PR$[/tex] is a directed line segment beginning at [tex]$P(-10,7)$[/tex] and ending at [tex]$R(8,-5)$[/tex]. Find point [tex]$Q$[/tex] on the line segment [tex]$PR$[/tex] that partitions it into the segments [tex]$PQ$[/tex] and [tex]$QR$[/tex] in the ratio [tex]$4:5$[/tex].

A. [tex]$\left(0,-\frac{1}{3}\right)$[/tex]

B. [tex]$\left(-2,-\frac{5}{3}\right)$[/tex]

C. [tex]$\left(-2, \frac{5}{3}\right)$[/tex]

D. [tex]$\left(-\frac{9}{2}, 3\right)$[/tex]


Sagot :

To find the point [tex]\( Q \)[/tex] on the line segment [tex]\( PR \)[/tex] that partitions it into segments [tex]\( PQ \)[/tex] and [tex]\( QR \)[/tex] in the ratio [tex]\( 4:5 \)[/tex], we use the section formula. Given points [tex]\( P(-10, 7) \)[/tex] and [tex]\( R(8, -5) \)[/tex], and the ratios [tex]\( m=4 \)[/tex] and [tex]\( n=5 \)[/tex], the section formula in two dimensions helps us determine the coordinates of [tex]\( Q \)[/tex]. The formula for the coordinates [tex]\((Q_x, Q_y)\)[/tex] is given by:

[tex]\[ Q_x = \frac{m \cdot R_x + n \cdot P_x}{m + n} \][/tex]
[tex]\[ Q_y = \frac{m \cdot R_y + n \cdot P_y}{m + n} \][/tex]

Substituting the given values:

1. Calculate [tex]\( Q_x \)[/tex]:

[tex]\[ Q_x = \frac{4 \cdot 8 + 5 \cdot (-10)}{4 + 5} \][/tex]
[tex]\[ = \frac{32 - 50}{9} \][/tex]
[tex]\[ = \frac{-18}{9} \][/tex]
[tex]\[ = -2 \][/tex]

2. Calculate [tex]\( Q_y \)[/tex]:

[tex]\[ Q_y = \frac{4 \cdot (-5) + 5 \cdot 7}{4 + 5} \][/tex]
[tex]\[ = \frac{-20 + 35}{9} \][/tex]
[tex]\[ = \frac{15}{9} \][/tex]
[tex]\[ = \frac{5}{3} \][/tex]

Thus, the coordinates of the point [tex]\( Q \)[/tex] are:

[tex]\[ Q = \left(-2, \frac{5}{3}\right) \][/tex]

Therefore, the correct option is:
C. [tex]\(\left(-2, \frac{5}{3}\right)\)[/tex]