求满足不等式组 17−8x3<2(3x−1)5≤4\dfrac{17-8x}{3} < \dfrac{2(3x-1)}{5} \le 4 的 xx 的取值范围。 由此,写出满足该不等式组的最小质数。

先不看答案,让 AI 诊断你卡在哪里?

它不会直接告诉你答案,而是问你卡在哪一步看看 AI 是怎么陪你一步步弄懂这道题的

完整解法

8(a)

1. Solve the left-hand inequality

17−8x3<2(3x−1)5\frac{17-8x}{3}<\frac{2(3x-1)}{5}
Multiply both sides by 1515:
5(17−8x)<6(3x−1)5(17-8x)<6(3x-1)
85−40x<18x−685-40x<18x-6
91<58x91<58x
x>9158x>\frac{91}{58}

2. Solve the right-hand inequality

2(3x−1)5≤4\frac{2(3x-1)}{5}\le 4
Multiply both sides by 55:
2(3x−1)≤202(3x-1)\le 20
6x−2≤206x-2\le 20
6x≤226x\le 22
x≤113x\le \frac{11}{3}

3. Combine the two inequalities into the final range

From the two conditions,
x>9158andx≤113.x>\frac{91}{58}\quad \text{and}\quad x\le \frac{11}{3}.
Hence,
9158<x≤113.\frac{91}{58}<x\le \frac{11}{3}.

答案

1≤x<79461 \le x < \frac{79}{46}

8(b)

1. Identify the smallest prime number satisfying the range from part (a)

From part (a),
1≤x<7946.1 \le x < \frac{79}{46}.
Since 7946≈1.72\frac{79}{46} \approx 1.72, there is no prime number in this interval. The smallest prime number is 22, but 2≮79462 \not< \frac{79}{46}.

Therefore, no prime number satisfies the inequalities.

答案

22

AI 分析,可能出错

用 AI 批改,圈出写错的那一步,并自动将你的薄弱点存入错题本,形成你的错因库。

同一知识点的其他题

  1. 1已知集合A={x|-5<2x+1<7},B={x|-2<x<4},则A∩B=( ) A. {x|-3<x<4} B. {x|-2<x<4} C. {x|-3<x<3} D. {x|-2<x<3}
  2. 2若关于xx的不等式 ⁣ ⁣{ ⁣ ⁣x−m⩽07−2x⩽1{ }\!\!\{\!\!{ }\begin{matrix} x-m\leqslant 0 \\ 7-2x\leqslant 1 \\\end{matrix}{ }的整数解共有44个,则mm的取值…
  3. 3若关于xx的分式方程4x−2−a2−x=2\dfrac{4}{x-2}-\dfrac{a}{2-x}=2的解为正整数,且关于yy的不等式组{y−22+5<2yy−a⩽0\begin{cases}{\dfrac{y-2}{2}+5< 2y}\\ {y-a\leqslant 0}\end{cases}…
  4. 4若函数f(x)=x2+2(a−1)x+2f(x)=x^{2}+2(a-1)x+2在区间(−∞,4](-∞,4]内递减,那么实数aa的取值范围为()(\quad) A. a⩽−3a\leqslant-3 B. a⩾−3a\geqslant-3 C. a⩽5a\leqslant 5…
  5. 5已知集合A={x∣3<x<6}A=\{x|3< x< 6\},B={x∣2<x<9}.(1)B=\{x|2< x< 9\}.(1)设全集U=RU=R,求∁U(A∩B)∁_{U}(A∩B); (2)已知集合C={x∣a<x<a+1}C=\{x|a< x< a+1\},若C⊆BC⊆B,求实数aa…