Point C is located at (1, 2) and point D is located at (−4, −2). Find the x value for the point that is 1 over 4 the distance from point C to point D. −0.25 3.25 −3.75 1.25
|dw:1431040858284:dw| so where do you think the point "x" is at there? or where would more or less would be in that graph
|dw:1431040254767:dw| here? idk >.<
@jdoe0001
hmmm well... close is 1/4 FROM C to D so|dw:1431041839195:dw| so notice the picture "x" is located from C to D 1/4 of the way that means that CX is 1/4 and XD is 3/4 so XD is 3 times bigger than CX or we can say that XD is at a 3:1 ratio to CX or the other way around, that CX is at 1:3 ratio to XD right?
right
so... let us use the ratio for those two sides a ratio of 1:3 from CX to XD thus |dw:1431042205150:dw| gimme one sec
\(\bf \textit{internal division of a line segment} \\ \quad \\ C(1,2)\qquad D(-4,-2)\qquad ratio1=1\qquad ratio2=3\qquad 1:3\\ \quad \\ \quad \\ \cfrac{C\cancel{ X }}{\cancel{ X }D}=\cfrac{1}{3}\implies 3\cdot C=1\cdot D\quad \implies 3(1,2)=1(-4,-2) \\ \quad \\ {\color{brown}{ X=\left(\cfrac{\textit{sum of "x" values}}{ratio1+ratio2}\quad ,\quad \cfrac{\textit{sum of "y" values}}{ratio1+ratio2}\right)}}\\ \quad \\ \qquad thus\qquad \\ \quad \\ X=\left(\cfrac{(3\cdot 1)+(1\cdot -4)}{1+3}\quad ,\quad \cfrac{(3\cdot 2)+(1\cdot -2)}{1+3}\right)\)
\[\frac{ 7 }{ 4 } , \frac{ 8 }{ 4 }\] ?
it comes out to that?
well.. check your sum again
1 * -4 = -4 1 * -2 = -2
oh instead of 7 it would be -1
and instead of 8 it would be 4
@jdoe0001
well... yes.... the first coordinate is off as well though recheck them both, see what you get
i still got -1/4 , 4/4
well... that's different than what you posted earlier though but that's correct, -1/4 and 4/4 or -1/4 and 1 :)
so how do i get one of the answer choices?
@jdoe0001
is it D?
@bibby
HI there, you still need help here?
yes
he never finished explaining
Start from the beginning or continue where you left off with the other helper?
all ik is that he made me solve this equation and i got -1/4 , 4/4
I didn't look back but was it this formula:
Ah wait I see what you did.
So yes, you basically have this already done. Your coordinates are (-1/4,1) and th x coordinate is what you need for this question. -1/4 is the same as -0.25. Therefore it is A.
omg thank you so much!!!!!
No need to thank me, you did all of the work! xD
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