Если что-то непонятно-обращайся)
1)а) х²+4х+1= х²+2х+2х+1=(х+1)²+2х
б) 3b²-12b+11=2b²+b²-6b+9-6b+2=2b²+(b-3) ²+2
<span>в) у</span>²<span>+2у=
у</span>²<span>+2у+1-1= (у+1)</span>²<span>-1</span>
2) а)-b²+6b-8= -(b²-6b+8)= -(b²-4b+2-2b+6)= -( (b<span>-2)</span>²<span>-2</span>b+6)= 2b-6-(b<span>-2)</span><span>²</span>
<span>б)1/4у</span>²<span>-у+2=1/4у</span>²<span>-у+1+1=(1/2у-1) </span>²<span>+1</span>
2 5/8-2 5/14*2/3 2 5/8-33/14*2/3 2 5/8- 11/7
---------------------------------- = ------------------------------ = -------------------------- =
(3 1/12+4 375/1000):19 8/9 (3 1/12+4 3/8):19 8/9 (3 2/24+4 9/24):19 8/9
2 5/8 - 1 4/7 2 35/56 - 1 32/56 1 3/56 1 3/56
---------------------- = ------------------------- = ----------------- = ---------- =
7 11/24 : 19 8/9 179/24 : 179/9 179/24*9/179 3/8
=59/56 : 3/8 = 59/56*8/3=59/21=2 17/21