Respostas

2014-08-10T09:09:38-03:00
3x+y= 4 >>> y= 4- 3x

2x- (4-3x)²= 1 >>> 2x-16 +24x-9x² =1 

-9x²+ 26x - 17=0 >>> " delta= b²-4.a.c" 

26²-4.-9. -17 >>>  676 - 612 >> delta = 64
x= -b + ou _ raiz de delta/ 2.a
x= -26+ 8/-18  x¹= 1   >>> x²=-34/-18

logo: 3x+ y = 4 >>> 3.1+ y=4 >> y = 4-3 >> y =1