13x-7y=19 & 7x-13y=31. x+y=_____
Answers
Answered by
15
13x-7y=19
91x - 49y = 133 [multiplying 7 to all]
-91x + 169y = - 403______ADD
120 y = - 270
y = - 9/4
7x + 117/4 = 31
7x = 7/4
x = 1/4
x + y = 1/4 + 7/4 = 2
pls brainliest
91x - 49y = 133 [multiplying 7 to all]
-91x + 169y = - 403______ADD
120 y = - 270
y = - 9/4
7x + 117/4 = 31
7x = 7/4
x = 1/4
x + y = 1/4 + 7/4 = 2
pls brainliest
Yashsavaliya:
Thanks
pls brainliest
ok
once again thank you so much
Answered by
8
13 x - 7 y = 19 ................ eq 1
7x - 13 y = 31 .................eq 2
subtract eq 2 from eq 1
we get,
13x - 7y - ( 7x - 13 y ) = 19 - 31
13x - 7y - 7x + 13y = -12
6x + 6y = -12
dividing by 6 , we get
x+ y = -2
7x - 13 y = 31 .................eq 2
subtract eq 2 from eq 1
we get,
13x - 7y - ( 7x - 13 y ) = 19 - 31
13x - 7y - 7x + 13y = -12
6x + 6y = -12
dividing by 6 , we get
x+ y = -2
Similar questions