Ответ:
A= 6x-3 B=2x+4
A*B= (6x-3)(2x+4)=(12x^2)+24x-6x-12= (12x^2)+18x-12
M=2x N=5x
M*N=2x*5x=10x^2
x=2
(A*B)-(M*N)= ((12x^2)+18x-12)-(10x^2))=((12*2^2)+18*2-12)-(10*2^2))=48+36-12-40=72-40=32
1) 6х^2 - 13х + 5 = 6( x - 1 2/3 )( x - 1/2 )
D = 169 - 120 = 49 = 7^2
X1 = ( 13 + 7 ) : 12 = 5/3 = 1 2/3
X2 = ( 13 - 7 ) : 12 = 1/2
2) 6x^2 - 4x - 10 = 6( x - 1 2/3 )( x + 1 )
D = 16 + 240 = 256 = 16^2
X1 = ( 4 + 16 ) : 12 = 5/3 = 1 2/3
X2 = ( 4 - 16 ) : 12 = - 1
3) сокращаем числитель и знаменатель дроби на 6( Х - 1 2/3 ), получили ( Х - 1/2 ) / ( Х + 1 )
4) Х = - 1
( - 1 - 1/2 ) / ( - 1 + 1 ) = 0