Question

Nilai y yang memenuhi x+y=2-y & x+y=2y-7,adalah cara subtitusi

Answer 1

 x+y=2-y
   x=2-y-y
   x=2-2y

x+y = 2y-7
(2-2y) + y = 2y-7
-2y+y-2y=-7-2
-3y=-9
y=3

x=2-2y=2-2(3)=2-6=-4

Answer 2

1. => x+y=2-y
    => x+y+y=2
    => x+2y=2

2. => x+y=2y-7
    => x+y-2y=-7
    => x-y = -7

Substitusi :
1. => x-y = -7
    => -y = -7 -x
    => y = 7+x

2. => x+2y=2
    => x+2(7+x) = 2
    => x+14+2x = 2
    => 3x+14 = 2
    => 3x = -12
    => x = -4

Jadi, nilai y = 7+x = 7 -4 = 3