X² + 4x = 5
x² + 4x - 5 = 0
D = 4² - 4·1·(-5) = 16 + 20 = 36
Ответ: -5.
+ - +
________₀_______₀_________
1,5 2 1/3
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Ответ : x ∈ (1,5 ; 2 1/3)
- 4 < = 1 - Х < = 5
- 4 - 1 < = - Х < = 5 - 1
- 5 < = - Х < = 4
- 4 < = Х < = 5
[ - 4 ; 5 ]
63/10 + 43/53 = (3359+430)/530 = 3769/530
ответ 7 целых 59/530