X²+5x-6=0
x=-6; x=1
78-3x=0
x=26
1) x<=-6<br>x²+5x-6<=78-3x<br>x²+8x-84<=0<br>D=64+336=400
x=(-8±20)/2
-14<=x<=6<br>-14<=x<=-6<br>
2) -6-x²-5x+6<=78-3x<br>-x²-2x-72<=0<br>x²+2x+72>=0
D=4-288<0<br>-6
3) 1x²+5x-6<=78-3x<br>-14<=x<=6<br>1
4) x>26
x²+5x-6<=-78+3x<br>x²-2x+72<=0<br>D=4-288<0<br>нет решений
ответ: [-14;6]