Question

Someone please help me!

Using the image below, find the y value for the point that divides the line segment CD into a ratio of 4:1.

Segment CD is shown. C is at 9, 6 and D is at 5, 1.

2

6.2

3

2.8

Answer 1

can someone help me please

Answer 2

call the point P

so

\[\frac{CP}{DP} = \frac{4}{1}\]

cross multiply and use

CP = 4DP

the end points C(9, 6) and D(5,1)

\[x = \frac{9 + 4 \times 5}{4 + 1}\]

and for y its

\[y = \frac{6 + 4 \times 1}{4 + 1}\]

just solve x and y to find the point P which divides the segment in the ratio 4:1

Answer 3

i don't understand

Answer 4

@campbell_st
Why do you say
cross multiply and use

CP = 4DP

Answer 5

well that way you always have the ratios in the correct proportions...

the formula is

\[x = \frac{nx_{1} + mx_{2}}{n + m}\]

by cross multiplying I get n and m in the right spots...

same process for y

Answer 6

Ah ok, I see. Thank you.