а) <span> (√6+<span> √10)*2<span> √2-2<span> √12=2<span> √12+2<span>√20-2<span>√12=<span> 2√20</span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span>б) (2√5-7)в квадрате+28√5=20-28√5+28√5=20</span></span></span></span></span></span></span></span>
3 1 6
__________=________________ - ___________
(х-3)² х+3 (х-3)(х+3)
3(х+3)=(х-3)² -6(х-3)
3х+9-х²+6х-9+6х-18=0
-х²+9х-18=0
х²-9х+18=0
Д=81-72=9
х1=(9+3+/2=6
х2=(9-3)/2=3 ОДЗ х≠3 х≠-3
ответ х=6
371-412х=-1277
412х=371+1277=1648
х=1648:412=4