1.
5.15² - 2*5.15*3.15+3.15² =
(5.15-3.15)² =
2² =
4 7.25² - 2.75² (7.25-2.75)(7.25+2.75) 4.5*10 452.a) (x+1)² -(x-2)(x+4)=x²+2x+1-(x²-2x+4x-8)=x²+2x+1-x²-2x+8=9б) (a+b)(a-b)(a²+b²)=(a²-b²)(a²+b²)=a⁴-b⁴3.(
5 -
1 ) :
3 = (
5 +
1 ) *
x-2y =(2x-4y 2y-x ) x-2y (2(x-2y) x-2y) 3=
5+2 *
x-2y =
7 = 1 ¹/₆ 2(x-2y) 3 6