Jawapan

2016-06-11T03:32:43+08:00
X+2y=2x²-5xy+2y²
x+2y=8
x=8-2y *
* in x+2y=2x²-5xy+2y²
(8-2y)+2y=2(8-2y)²-5y(8-2y)+2y²
8=2(64-32y+4y²)-40y+10y²+2y²
8=128-64y+8y²-40y+12y²
8=128-104y+12y²
12y²-104y+120=0
y=7.296,1.371