<span>а) 9х^2-7x-2=0</span>
<span>21+10n+n²=(7+n)(3+n)
</span>14-9k+k²=(7-k)(2-k)
42-13b+b²=(6-b)(7-b)
<span>48-14c+c²=</span>(6-c)(8-c)
1) √27 * (-sin60) + 4cos60 + tg45 = √27 * (-<span>√3\2) + 2 + 1 = -4.5 + 3 = -1.5
2) 2sin(360+30) - 5cos(360+60) - 10tg720 = 2sin30 - 5cos60 - 0 = 1 - 2.5 = -1.5</span>