(0,9х+40/27у)²=0,81х²+8/3+1600/729у²
= 3 + √7·2· log7/log4= 3 + √7·2·1/2log2 = 3 + √7/log2
осн. = 7 осн.7 осн.7
1)х²+2х-3≤0
х1+х2=-2 и х1*х2=-3⇒х1=-3 и х2=1
+ _ +
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-3 1
х∈[-3;1]
2)(2x+1)²>0
x=-1
+ +
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-1
x∈(-≈;-1)U(-1;≈)