x(x-4)+(3-x)(x3+x)-6x= -21
При x=3
3*(3-4)+(3-3)*(3*3+3)-6*3
1) 3-4 = -1
2) 3-3= 0
3) 3*3+3= 9+3= 12
4) 3*-1 = -3
5) 0*12=0
6) 6*3 = 18
7) -3+0= -3
8) -3-18 = -21
x(x-4)+(3-x)(x3+x)-6x= -21
При x=3
3*(3-4)+(3-3)*(3*3+3)-6*3
1) 3-4 = -1
2) 3-3= 0
3) 3*3+3= 9+3= 12
4) 3*-1 = -3
5) 0*12=0
6) 6*3 = 18
7) -3+0= -3
8) -3-18 = -21