6) 5(1 + 2x) - (2x - 1) = 7
5 + 10x - 2x + 1 = 7
10x - 2x = 7 - 5 - 1
8x = 1
x = 1 : 8 = 0,125
7) 11(1 - 2x) - 8(3x - 5) = 1 + 4x
11 - 22x - 24x + 40 = 1 + 4x
- 22x - 24x - 4x = 1 - 11 - 40
- 50x = - 50
x = - 50 : (- 50) = 1
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>