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mayankdevnani
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Given: 3x4y=7 and x+cy=13 , for what value of "c" will the two equations not have a solution?
 2 years ago
 2 years ago
mayankdevnani Group Title
Given: 3x4y=7 and x+cy=13 , for what value of "c" will the two equations not have a solution?
 2 years ago
 2 years ago

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mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
options are : a) \[\frac{3}{4}\] b)\[\frac{4}{3}\] c) \[4\] d) \[\frac{4}{3}\]
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
i think there is easier way out....
 2 years ago

ash2326 Group TitleBest ResponseYou've already chosen the best response.3
Rewrite first equation \[x\frac{4}{3}y=7\] for no solution we need to have parallel lines second equation \[x+cy=13\] compare this with the first \[c=\frac{4}{3}\]
 2 years ago

ParthKohli Group TitleBest ResponseYou've already chosen the best response.0
@hartnn: Oh yeah
 2 years ago

sauravshakya Group TitleBest ResponseYou've already chosen the best response.1
WELL FOLLOW @ash2326 THAT ONE MUCH EASIER..... agreed with @hartnn
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
no solution is of the form: ax+b=c ax+b=d
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
@ash2326 gd and then
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
and why would that have an infinite # of solutions?
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.2
because ax+b=c and ax+b=c are satisfied by infinite number of points (x,y) simultaneously.
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
ash2326's solution is mostly correct
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
this one doesn't satisfy that
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
ok! then @Zarkon
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
3x4y=7 and x+cy=13 \[x\frac{4}{3}y=\frac{7}{3}\] \[x+cy=13\]
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
yaa ... i also agree with @Zarkon don't you @mathslover
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
if c=4/3 then you get \[x\frac{4}{3}y=\frac{7}{3}\] and \[x\frac{4}{3}y=13\] ie \[\frac{7}{3}=13\]
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
thus no solution
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
isn't like this \[3x4y=7\] \[3x=74y\] \[xy=\frac{7}{12}\] \[x=\frac{7}{12}+y\]
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
and then solve it
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
What I did is this : \[\large{7+4y = 3(13cy)}\] \[\large{7+4y=393cy}\] \[\large{32= 4y+3cy}\] We have to find the value of c when the RHS becomes zero which will give no solution. \[\large{4y+3(c)(y)=0}\] \[\large{c = \frac{4y}{3y}}\] \[\large{c=\frac{4}{3}}\] hence at c = 4/3 we get no solutions for the variables in the given two equations .
 2 years ago

sauravshakya Group TitleBest ResponseYou've already chosen the best response.1
@mayankdevnani what r u doing?
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
@mayankdevnani you need to concentrate hardly on understanding questions... You are solving for x or y but in the question we have to find the value for c which makes the solutions for the equation as null set.
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
how did you get it......... @mathslover
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
btw , @Zarkon sir , was my method acceptable? I know there are easy methods too.. but that is what I did..
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
ANSWER is correct... but i did'nt understand..... plz tell me once again.....
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
@mayankdevnani where are you not getting ?
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
step by step
 2 years ago

sauravshakya Group TitleBest ResponseYou've already chosen the best response.1
THAT WAS exactly what I was thinking @mathslover THAT IS ABSOULETLY CORRECT
 2 years ago

Zarkon Group TitleBest ResponseYou've already chosen the best response.0
yes...your way is fine
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
OK thanks @sauravshakya Let us wait for honorable zarkon sir ..
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
OK thanks a lot @Zarkon .. that fine made a lot sense sir.. :)
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
@mathslover how did you get it \[7+4y=1(13cy)\]
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
ya.. but how??
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
that will be a prallal line
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
3x4y = 7 x = (7+4y) / 3 and then : x + cy = 13 x = 13cy 13cy = (7+4y)/3 (since they are equal to x) 3(13cy) = 7+4y
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.5
got it @mayankdevnani ?
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
just put 4/3 at C and you will have a parallel set of line and parallel set of lines have no solution
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
@mayankdevnani clear?
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
ok... @mathslover
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
3x4y=7 and 3x4y=39 are parallel lines how could they have a solution ..they intersect nowhere
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
neither do they overlap
 2 years ago

mayankdevnani Group TitleBest ResponseYou've already chosen the best response.0
thnx.... @Zarkon @ghazi @sauravshakya @ash2326 but special thnx to @mathslover
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
@mathslover is my approach correct?
 2 years ago

sauravshakya Group TitleBest ResponseYou've already chosen the best response.1
Isnt your method same as @ash2326 's method........ @ghazi
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
i didn't see ...i just came here read the question and identified these are parallel lines...i guess yes both have same solution and we don't need to solve anything because already it is visible that it's case of parallel line when c= 4/3 hence no solution
 2 years ago

ghazi Group TitleBest ResponseYou've already chosen the best response.1
yes it is similar to that of @ash2326
 2 years ago
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