X^2 - 16X + 63 = ( X - 9)*( X - 7 )
D = 256 - 252 = 4 ; √ D = 2
X1 = ( 16 + 2 ) : 2 = 9
X2 = ( 16 - 2 ) : 2 = 7
3X^2 - 5X - 2 = 3 * ( X - 2 ) * ( X + 1 )
D = 25 + 24 = 49 ; √ D = 7
X1 = ( 5 + 7 ) : 6 = 2
<span>X2 = ( 5 - 7 ) : 6 = - 1/3</span>
А)4а во 2 (2а во 2 -3b в 3+1)
б)(х-6у)-(5-у)
Решение смотри на фотографии
14Х-(12Х-6+11Х)+2Х=Х+13-8Х
14Х-12Х+6-11Х+2Х=Х+13-8Х
2Х+2Х-11Х+7Х=+13-6
11Х-11Х=7
0Х≠7!