- 13 ≤ 4x +
3 ≤ 18
log₃ (x² - 7) ≥ 2
- 13 -
3 ≤ 4x ≤ 18 - 3
x² -
7 ≥ 3²
-
16 ≤ 4x ≤ 15
x² ≥
9 + 7
1)
- 4 ≤ x ≤ 3,75
x²
≥ 16
x₁ = - 4
x₂ = 4
+
-
+
-------------------------------------------------------------->
- 4
4
x
2 )
x∈( - ≈; - 4] [4 ; + ≈)
Объединяя
1) и 2) получаем:
х∈ Ø