<span>7x</span>²<span> + 6x + 1 = 0</span>
D = 6²<span> - 4·7·1 = 8</span>
<span><span><span>x1 = (</span><span>-6 - √8)/2*7</span> = <span><span>-3/</span>7</span> - <span>17</span><span>√2</span> ≈ -0.63060
</span></span><span><span>x2 = (</span><span>-6 + √8)/2*7</span> = <span><span>-3/</span>7</span> + <span>17</span><span>√2</span> </span>≈ -0.22654<span>
</span>
X-1 первое число, х второе, х+1 третье
(х-1)^2 +65=х(х+1)
х^2 -2х +1 +65 =х^2 + х
3х=66
х=22 второе число, 21 первое, 23 третье
20+ 2=22 18+ 4=22 16+6=22
(х-1)*(х+2)-х (х+3)=3х
х2+2х-х-2-х2-3х=3х
-2х-2=3х
2х+3х=-2
5х=-2
х=-0,2