36c² - 48cy + k = (6c)² - 2 * 6c * 4y + (4y)² = 36c² - 48cy + 16y² =
= (6c - 4y)²
k =16y²
<span>5-3х<17-5х</span>
<span>-3x+5x<17-5</span>
<span>2x<12</span>
<span>x<6</span>
<span>xe(-oo.6)</span>