14444 + 7869 + 64 - (-69)+ 7685

= 22313 + 64 + 69 + 7685

= 22377 + 69 + 7685

= 22446 + 7685

= 30131

295849300

a: TA có: \(x^6\ge0\forall x\)

\(x^2\ge0\forall x\)

\(\left|x-3\right|\ge0\forall x\)

Do đó: \(x^6+x^2+\left|x-3\right|\ge0\forall x\)

=>\(x^6+x^2+\left|x-3\right|+1\ge1>0\forall x\)

=>Đa thức f(x) không có nghiệm

b: \(-x^2\le0\forall x\)

\(-\left|x+5\right|\le0\forall x\)

Do đó: \(-x^2-\left|x+5\right|\le0\forall x\)

=>\(-x^2-\left|x+5\right|-1\le-1<0\forall x\)

=>Đa thức g(x) không có nghiệm

Ta xét từng đa thức (biểu thức) trên ℝ.

a) \(f \left(\right. x \left.\right) = x^{6} + x^{2} + \mid x - 3 \mid + 1\)

Với mọi \(x \in \mathbb{R}\):

• \(x^{6} \geq 0\)
• \(x^{2} \geq 0\)
• \(\mid x - 3 \mid \geq 0\)
• \(1 > 0\)

Do đó:

\(f \left(\right. x \left.\right) = x^{6} + x^{2} + \mid x - 3 \mid + 1 \geq 0 + 0 + 0 + 1 = 1\)

Suy ra:

\(f \left(\right. x \left.\right) \geq 1 > 0 \forall x \in \mathbb{R}\)

Vì \(f \left(\right. x \left.\right)\) luôn dương nên phương trình:

\(f \left(\right. x \left.\right) = 0\)

vô nghiệm trên ℝ.

b) \(g \left(\right. x \left.\right) = - x^{2} - \mid x + 5 \mid - 1\)

Với mọi \(x \in \mathbb{R}\):

• \(x^{2} \geq 0 \Rightarrow - x^{2} \leq 0\)
• \(\mid x + 5 \mid \geq 0 \Rightarrow - \mid x + 5 \mid \leq 0\)
• \(- 1 < 0\)

Do đó:

\(g \left(\right. x \left.\right) = - x^{2} - \mid x + 5 \mid - 1 \leq 0 + 0 - 1 = - 1\)

Suy ra:

\(g \left(\right. x \left.\right) \leq - 1 < 0 \forall x \in \mathbb{R}\)

Vì \(g \left(\right. x \left.\right)\) luôn âm nên phương trình:

\(g \left(\right. x \left.\right) = 0\)

vô nghiệm trên ℝ.

Kết luận

• a) \(f \left(\right. x \left.\right) = 0\) vô nghiệm.
• b) \(g \left(\right. x \left.\right) = 0\) vô nghiệm.

kkkk

Câu hỏi: Thành phố nào dưới đây ở Cao nguyên miền Trung nước ta.

Đáp án B:Buôn Ma Thuột

đảm bảo không dùng AI

B

doppelganger.

The doppelganger looks like him: Người giống hệt anh ấy.

Nên dùng doppelganger

tính từ

arrogant

mystery cũng là tính từ>

Giải:

Làm cánh đồng hết cỏ trong một giờ cần:

9 x 20 = 180 (người)

Nếu 15 người làm thì làm trong:

180 : 15 = 12(giờ)

Kết luận:

Nếu 15 người làm thì sẽ sạch cỏ trong 12 giờ

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