Ответ:

N1.

(2x-3y)²=(2x)²-2*2x*3y+(3y)²=4x²-12xy+9y²

(a²-3)²=(a²)²-2*a*3+3²=a⁴-6a+9

N2.

(5a+7b)²-70ab=(5a)²+2*5a*7b+(7b)²-70ab=25a²+70ab+49b²-70ab=25a²+49b²

(8a-b)²-64a²=(8a)²-2*8a*b+b²-64a²=64a²-16ab+b²-64a²=-16ab+b²

N3.

(3b-1)(3b+1)=9b²-1

(5b+6)(5b-6)=25b²-36

(7-1/2a)(7+1/2a)=49-1/4a²

N4.

36m²-100n²=4(9m²-25n²)=4(3m-5n)(3m+5n)

0,04x²-1,69y²=0,01(4x²-169y²)=0,01(2x-13y)(2x+13y)

1,44a²-12=0,48(3a²-25)