................................
.
<span>a(a+2)(a-2)-(a-3) (a^2+3a+9 ) =а(а²-4)-(а³-3³)=а³-4а-а³+27=-4а+27</span>
углы<span> </span><span>САН и </span><span> </span><span>МАС</span><span> смежные</span>
2.6x+x=180
3.6x=180
x=180/3.6
x=50-CAH
180-50=130-MAC
25х²+90х+81=0
D=8100-8100=0
x=-90/50
<span>x=-1.8</span>