3)(a+b)(a²-b²)=(a-b)(a+b)²
(a+b)(a-b)(a+b) = (a-b)(a+b)²
(a+b)²(a-b)=(a-b)(a+b)²
4.1)(2x-5)²-(2x-3)²=0
(2x-5-2x+3)(2x-5+2x-3)=0
-2(4x-8)=0
4x=8
x=2
4.2)x²-(x+3)(x-3)=3x
x²-(x²-9)-3x=0
9 = 3x
x=3
4.3)(2x-1)²-4(x-2)(x+2)=0
4x²-4x+1-4x²+4=0
5 = 4x
x = 0,8
4.4)(x²-1)(x²+3)=(x²+1)²+x
x⁴+2x²-3 = x⁴+2x²+1+x
x=-4