<span>у= -5х+4
</span><span>а) у=-6
- 6 = - 5x + 4
- 5x = - 10
x = 2
</span><span>б) у= 19
19 = - 5x + 4
- 5x = 15
x = - 3 </span>
Биквадратное уравнение. Бери d=x2, и решай как d2-8d+16=0
S = <span>12</span>d1<span> · </span>d2 = <span>12</span><span> · 8 · 12 = 48</span>