Помогите!!!!!!!!!!!!!

Question

Помогите!!!!!!!!!!!!!

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Answer 1

У=-5х+15
1) у>0
-5x+15>0
-5x>-15
x<3<br>x∈(-∞;3)

2) y<0<br>-5x+15<0<br>-5x<-15<br>x>3
x∈(3;+∞)

3) -5x+15≥-15
-5x≥-30
x≤6
(-∞;-6]

4) -5x+15≤25
-5x≤10
x≤-2
x∈(-∞;-2]