3) 
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-----------o------------o------->x
-0.4 3
x∈(-0.4; 3)
1) 5х+2>0
5x > -2
x > -2/5
x > -0.4
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--------o------------>x
-0.4
x∈(-0.4; +∞)
2) 1/4 x >1 | * 4
x > 4
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--------o---------->x
4
x∈(4; +∞)