Question

MEDAL AND FAN

If the midpoint between (18, y) and (20, -15) is (19, -5), find the value of y.

Answer 1

You're basically cross multiplying I believe. \[\frac{ x }{ y }\]

Answer 2

So \[\frac{ 18 }{ y } + \frac{ 20 }{ -15 } = \frac{ 19 }{ -5 }\]

Answer 3

Right?

Answer 4

Well the midpoint formula is\[[(x_1 + x_2)/2 , (y_1 + y_2)/2]\] And you have both X's but only one Y. Yet you also have the final answer.

Answer 5

yeah your right

Answer 6

Yes your right

Answer 7

Cool :) So now you just solve for y.

Answer 8

Right so cross multiply \[18 \times - 15\] Then take that answer an divide it by 20

Answer 9

man I'm to slow

Answer 10

-270 /20 is -13.5?

Answer 11

is that the anwser

Answer 12

no not quite... think of it this way. The difference between the X's is one

Answer 13

You already have the x-coordinate of the midpoint. Focus on the y-coordinate.
\[y _{midpoint}=\frac{ (unknown~y)+(-15) }{ 2 }=-5\]

Answer 14

solve this for "unknown y."

Answer 15

I'm confused:/

Answer 16

No multiplication here. And don't focus on the midpoint's x-coordinate further; it is -5.

What do you understand and what do you not understand?

Answer 17

this whole finding the mid point is new to me

Answer 18

Solve this:\[\frac{ y-15 }{ 2 }=-5\]

Answer 19

that's negative 3 right

Answer 20

no its not I don't know how I got that

Answer 21

Please look up "midpoint." I'm sure you'll find the appropriate formulas.

For the y-coordinate of the midpoint, y ou're working with \[\frac{ y _{1}+y _{2} }{ 2 }=y _{midpoint}\]

Answer 22

In this case you already know that the y-coord. of the midpoint is -5.

So, solve \[\frac{ y _{endpoint}-15 }{ 2 }=-5\]

Answer 23

Start by mult. both sides of this equation by 2. This will eliminate the fraction.

Answer 24

ok so -30 =-10

Answer 25

-30=-10 is not a true equation. Mind trying again?

You have ONE unknown; it is y.

y+(-15)
------- = -5
2

Multiply (-5) by 2; you get -10.

Multiply

y - 15
----- by 2. What do you get? The fraction should disappear.
2