# 7/x + 4y = 1 and 5/x + 2y = -1 find the value of x=? and y=?

2
by sayandeb

2015-11-17T13:17:59+05:30
7(1/x)+4y=1 5(1/x)+2y=-1 Let 1/x=a 7a+4y=1........(1) 5a+2y=-1......(2) Multiply eqn 2 with 2 We get, 7a+4y=1 10a+4y=-2..subtract the equations .................. -3a=1 a=-1/3 Put a =-1/3 in any of the equations and solve for y Y=+2 As a is -1/3 x is -3 therefore,So x=-3 and y=2
kk
no thnx between friends
kk
what is the value of x then ??... is it -3 only
Ya
2015-11-17T13:22:26+05:30
7/x + 4y = 1
7 + 4y =1x
4y = 1x - 7
y = (1x - 7)/4------------------------------(1)
and ,
5/x + 2y = -1
5 + 2y = -1x
x = -5 - 2y----------------------------------(2)
by putting the value of x in equation (1)
y = { 1 (-5 - 2y )-7 } /4
y = - 5 - 2y - 7 / 4
y = - 12 - 2y / 4
y = - 12/4 - 2y/4
y = - 3 - y/2
y + y/2 = -3
(2y + 1y) /2 = -3
3y/2 = - 3
3y = - 3 * 2
3y = - 6
y = -6 / 3
y = -2
therefore value of y = -2
now value of x ,
by putting the value of y in equation (2)
x = - 5 - 2y
x = - 5 -2 * -2
x = - 5 + 2
x = - 3
therefore the value of x = -3
i hope that my answer will help u............................^_^
Y is + 2
not -2
ok
:)
:) ok