Нет, не верно, т.к.
<span>-(-2,7)=2,7
2,7>0, т.е</span>
<span><span>-(-2,7)>0</span>
</span>
4x-7y=30
4x-5y=90
отнимем
-2у=-60
у=30
4x-150=90
4x=240
x=60
(60;30)
X-2 ≤ -6.25/(x+3)
(x-2)*(x+3) ≤6.25
x² + 3x -2x -6 ≤6.25
x² +x -6 ≤ 6.25
x² + x ≤ 6.25 +6
x² +x ≤12.25
x(x + 1) ≤12.25
x ≤12.25 или х≤11.25