<span><span>(5a</span></span>⁹<span><span>-3a</span></span>⁷<span><span>)/4a</span></span>⁸<span><span>=
a</span></span>⁷<span><span>(5a</span></span>²<span><span>-3)/4a</span></span>⁸<span><span>=(5a</span></span>²<span><span>-3)/4a
</span>при а=-1
получается:
(5*(-1)</span>²<span>-3)/4(-1)=5-3/-4=-1/2=-0,5</span>
Х - 2у = 7
+
х + 2у = -1
____
2х = 6
х = 3
х = 3
3 - 2у = 7
х = 3
-2у = 4
х = 3
у = -2
ОТВЕТ: (3;-2)