Question

Point R divides in the ratio 1 : 3. If the x-coordinate of R is -1 and the x-coordinate of P is -3, what is the x-coordinate of Q?
A.

B.
3
C.
5
D.
6
E.
-9

Answer 1

Answer:

C. 5

Step-by-step explanation:

Point R divides the line segment PQ internally. The x-coordinate of the point which divides the line segment in ration m:n internally can be calculated as:

$x=(\frac{mx_{2}+nx_{1}}{m+n} )$

Here, x1 is the x-coordinate of 1st point, x2 is the x-coordinate of 2nd point, x is the x-coordinate of point dividing the segment. We have all the values except x2. Using the given values in above formula, we get:

$-1=\frac{x_{2}+3(-3) }{1+3} \\ \\-4=x_{2}-9\\\\ 5=x_{2}$

Thus the x-coordinate of point Q will be 5

The x-coordinate of Q is 5.