b) (ab-a)(2ab+ba)= 2a²b²+a²b²-2a²b-a²b=2a²b²-3a²b c) 4(2a-b)(2a+4b)-(3a-2b)(3b-2a)=4(2a²+8ab-2ab-4b²)-(3ab-6a²-6b²+2ab)= = 8a²+32ab-8ab-16b²-3ab+6a²+6b²-2ab=14a²-10b²+19ab
b) (ab-a)(2ab+ba)= 2a²b²+a²b²-2a²b-a²b=2a²b²-3a²b c) 4(2a-b)(2a+4b)-(3a-2b)(3b-2a)=4(2a²+8ab-2ab-4b²)-(3ab-6a²-6b²+2ab)= = 8a²+32ab-8ab-16b²-3ab+6a²+6b²-2ab=14a²-10b²+19ab
3(a+b)+(a-2b)=3a+3b+a-2b
4x(x-y-z)-2x(4x-y+z)=4x²-4xy-4xz-8x²+2xy-2xz=-4x²-2xy-6xz
zad.2
a) (x-y)(5x+6y)=5x²+6xy-5xy-6y²=5x²+xy-6y²
b) (ab-a)(2ab+ba)= 2a²b²+a²b²-2a²b-a²b=2a²b²-3a²b
c) 4(2a-b)(2a+4b)-(3a-2b)(3b-2a)=4(2a²+8ab-2ab-4b²)-(3ab-6a²-6b²+2ab)=
= 8a²+32ab-8ab-16b²-3ab+6a²+6b²-2ab=14a²-10b²+19ab
3(a+b)+(a-2b)=3a+3b+a-2b
4x(x-y-z)-2x(4x-y+z)=4x²-4xy-4xz-8x²+2xy-2xz=-4x²-2xy-6xz
zad.2
a) (x-y)(5x+6y)=5x²+6xy-5xy-6y²=5x²+xy-6y²
b) (ab-a)(2ab+ba)= 2a²b²+a²b²-2a²b-a²b=2a²b²-3a²b
c) 4(2a-b)(2a+4b)-(3a-2b)(3b-2a)=4(2a²+8ab-2ab-4b²)-(3ab-6a²-6b²+2ab)=
= 8a²+32ab-8ab-16b²-3ab+6a²+6b²-2ab=14a²-10b²+19ab
DAJ MI NAJ!!!