<span>(sin15-cos15)⁴=((sin15-cos15)²)²=(sin²15-2sin15cos15+cos²15)²=(1-sin30)=(½)²=¼</span>
X. ab
___________ : ___________ = 0
(a-b) (a+b). a(a-b)
x. a(a-b)
___________ . ___________ = 0
(a-b) (a+b). ab
сокращаем
x. 1
_____ . _____ = 0
a+b. b
x
_____ = b
a+b
x= ab+ b^2
вроде бы так