Cho <span class="MathJax_Preview" style="color: inherit;"><span class="MJXp-math" id="MJXp-Span-1"><span class="MJXp-mstyle" id="MJXp-Span-2"><span class="MJXp-mi MJXp-italic" id="MJXp-Span-3">a</span><span class="MJXp-mo" id="MJXp-Span-4" style="margin-left: 0.333em; margin-right: 0.333em;">></span><span class="MJXp-mn" id="MJXp-Span-5">0</span><span class="MJXp-mo" id="MJXp-Span-6" style="margin-left: 0em; margin-right: 0.222em;">,</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-7">b</span><span class="MJXp-mo" id="MJXp-Span-8" style="margin-left: 0.333em; margin-right: 0.333em;">></span><span class="MJXp-mn" id="MJXp-Span-9">0</span><span class="MJXp-mo" id="MJXp-Span-10" style="margin-left: 0em; margin-right: 0.222em;">,</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-11">c</span><span class="MJXp-mo" id="MJXp-Span-12" style="margin-left: 0.333em; margin-right: 0.333em;">></span><span class="MJXp-mn" id="MJXp-Span-13">0</span></span></span></span><span id="MathJax-Element-1-Frame" class="mjx-chtml MathJax_CHTML MJXc-processed" tabindex="0" style="font-size: 127%;"><span id="MJXc-Node-1" class="mjx-math"><span id="MJXc-Node-2" class="mjx-mrow"><span id="MJXc-Node-3" class="mjx-mstyle"><span id="MJXc-Node-4" class="mjx-mrow" style="font-size: 144%;"><span id="MJXc-Node-5" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.199em; padding-bottom: 0.298em;">a</span></span><span id="MJXc-Node-6" class="mjx-mo MJXc-space3"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.249em; padding-bottom: 0.396em;">></span></span><span id="MJXc-Node-7" class="mjx-mn MJXc-space3"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.396em; padding-bottom: 0.347em;">0</span></span><span id="MJXc-Node-8" class="mjx-mo"><span class="mjx-char MJXc-TeX-main-R" style="margin-top: -0.145em; padding-bottom: 0.544em;">,</span></span><span id="MJXc-Node-9" class="mjx-mi MJXc-space1"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.495em; padding-bottom: 0.298em;">b</span></span><span id="MJXc-Node-10" class="mjx-mo MJXc-space3"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.249em; padding-bottom: 0.396em;">></span></span><span id="MJXc-Node-11" class="mjx-mn MJXc-space3"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.396em; padding-bottom: 0.347em;">0</span></span><span id="MJXc-Node-12" class="mjx-mo"><span class="mjx-char MJXc-TeX-main-R" style="margin-top: -0.145em; padding-bottom: 0.544em;">,</span></span><span id="MJXc-Node-13" class="mjx-mi MJXc-space1"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.199em; padding-bottom: 0.298em;">c</span></span><span id="MJXc-Node-14" class="mjx-mo MJXc-space3"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.249em; padding-bottom: 0.396em;">></span></span><span id="MJXc-Node-15" class="mjx-mn MJXc-space3"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.396em; padding-bottom: 0.347em;">0</span></span></span></span></span></span></span><script type="math/tex" id="MathJax-Element-1">\Large a>0, b>0, c>0</script> là các số thực khác 0 thỏa mãn $\Large 5^a=

Cho a>0,b>0,c>0a>0,b>0,c>0 là các số thực khác 0 thỏa mãn $\Large 5^a=

4.6/5

Tác giả: Thầy Tùng

Đăng ngày: 18 Aug 2022

Lưu về Facebook:

Câu hỏi:

Cho a>0,b>0,c>0a>0,b>0,c>0 là các số thực khác 0 thỏa mãn 5a=15b=45c5a=15b=45c. Tính T=ba+bcT=ba+bc

Đáp án án đúng là: C

Lời giải chi tiết:

Chọn C

Giả sử 5a=15b=45c=t5a=15b=45c=t {a=log5tb=log15tc=log45t

Ta có: T=ba+bc=log15tlog5t+log15tlog45t=log155+log1545=log15225=2