X^2+15x>0
x(x+15)>0
x=0 или x+15=0
х=-15
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-15 0
(-∞.-15) U (0,+<span>∞)</span>
А)-x-2=9x
-x-9x=2
-10x=2
x=-10:2
x=-5
б)-6x-5=4x
-6x-4x=5
-10x=5
x=-10:5
x=-2
в)-x+7=6x
-x-6x=7
-7x=7
x=-7:7
x=1
г)-7x+8=9x
-7x-9x=-8
-16x=-8
x=-16:(-8)
x=2
д)-x+2=4x
-x-4x=-2
-5x=-2
x=-5:(-2)
x=2,5
(x^2-4x+3)(x-5)=x^3-4x^2+3x-5x^2+20x-15=x^3-9x^2+23x-15
<span>(5^7)^2 * 5^9/ 5^25=5^14*5^9\5^25=5^23\5^25=1\5^2=1\25</span>
<span>(9x^6 - 4x^3) - (x^3 - 9) - (8x^6 - 5x^3) = x^6 +9
</span><span>9x^6 - 4x^3 - x^3 +9 - 8x^6 +5x^3 = x^6 +9
находим подобные слагаемые (</span>9x^6 -8x^6 =x^6 ..........- 4x^3 - x^3 +<span>5x^3=0)
</span>
x^6 +9=<span>x^6 +9</span>