a) 4x-6x+5=0
-2x+5=0
-2x=-5
X=5/2=2,5
б) (2x+5x+1)(2x+5x+3)+1=0
(7x+1)(7x+3)+1=0
49x²+21x+7x+3+1=0
49x²+28x+4=0
(7x+2)²=0
7x+2=0
7x=-2
X=-2/7
._.
a) 4x-6x+5=0
-2x+5=0
-2x=-5
X=5/2=2,5
б) (2x+5x+1)(2x+5x+3)+1=0
(7x+1)(7x+3)+1=0
49x²+21x+7x+3+1=0
49x²+28x+4=0
(7x+2)²=0
7x+2=0
7x=-2
X=-2/7
._.