1)25y^2 - a^2 = (5y - a)(5y + a)
2)c^2 + 4bc + 4b^2 = ( c+2b)(c+2b)
25х²=0
х=0
отв:0
,,,,,,,,,,,,,,,,,,
=(-12)a^2+6a+4
при a=-2
48+12+4=56
-3х+1-3х-9=-2(1-х)+2
-6х+1-9=-2+2х+2
-6х-8=2х
-6х=2х+8
-6х-2х=8
-8х=8
х=1
4-4x=6-7x
-4x+7x=6-4
3x=2
x=2/3
y=4-8/3=4/3
(2/3;4/3)