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-mo" id="MJXp-Span-3" style="margin-left: 0em; margin-right: 0em;">(</span><span class="MJXp-mn" id="MJXp-Span-4">4</span><span class="MJXp-msubsup" id="MJXp-Span-5"><span class="MJXp-mi MJXp-italic" id="MJXp-Span-6" style="margin-right: 0.05em;">x</span><span class="MJXp-mn MJXp-script" id="MJXp-Span-7" style="vertical-align: 0.5em;">2</span></span><span class="MJXp-mo" id="MJXp-Span-8" style="margin-left: 0.267em; margin-right: 0.267em;">+</span><span class="MJXp-mn" id="MJXp-Span-9">4</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-10">x</span><span class="MJXp-mo" id="MJXp-Span-11" style="margin-left: 0.267em; margin-right: 0.267em;">−</span><span class="MJXp-mn" id="MJXp-Span-12">3</span><span class="MJXp-msubsup" id="MJXp-Span-13"><span class="MJXp-mo" id="MJXp-Span-14" style="margin-left: 0em; margin-right: 0.05em;">)</span><span class="MJXp-mn MJXp-script" id="MJXp-Span-15" style="vertical-align: 0.5em;">2</span></span><span class="MJXp-mo" id="MJXp-Span-16" style="margin-left: 0.267em; margin-right: 0.267em;">−</span><span class="MJXp-mo" id="MJXp-Span-17" style="margin-left: 0em; margin-right: 0em;">(</span><span class="MJXp-mn" id="MJXp-Span-18">4</span><span class="MJXp-msubsup" id="MJXp-Span-19"><span class="MJXp-mi MJXp-italic" id="MJXp-Span-20" style="margin-right: 0.05em;">x</span><span class="MJXp-mn MJXp-script" id="MJXp-Span-21" style="vertical-align: 0.5em;">2</span></span><span class="MJXp-mo" id="MJXp-Span-22" style="margin-left: 0.267em; margin-right: 0.267em;">+</span><span class="MJXp-mn" id="MJXp-Span-23">4</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-24">x</span><span class="MJXp-mo" id="MJXp-Span-25" style="margin-left: 0.267em; margin-right: 0.267em;">+</span><span class="MJXp-mn" id="MJXp-Span-26">3</span><span class="MJXp-msubsup" id="MJXp-Span-27"><span class="MJXp-mo" id="MJXp-Span-28" style="margin-left: 0em; margin-right: 0.05em;">)</span><span class="MJXp-mn MJXp-script" id="MJXp-Span-29" style="vertical-align: 0.5em;">2</span></span><span class="MJXp-mo" id="MJXp-Span-30" style="margin-left: 0.333em; margin-right: 0.333em;">=</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-31">m</span><span class="MJXp-mo" id="MJXp-Span-32" style="margin-left: 0em; margin-right: 0.222em;">.</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-33">x</span><span class="MJXp-mo" id="MJXp-Span-34" style="margin-left: 0em; margin-right: 0em;">(</span><span class="MJXp-mi MJXp-italic" id="MJXp-Span-35">x</span><span class="MJXp-mo" id="MJXp-Span-36" style="margin-left: 0.267em; margin-right: 0.267em;">+</span><span class="MJXp-mn" id="MJXp-Span-37">1</span><span class="MJXp-mo" id="MJXp-Span-38" style="margin-left: 0em; margin-right: 0em;">)</span></span></span></span><script type="math/tex" id="MathJax-Element-1">\Large (4x^2+4x-3)^2-(4x^2+4x+3)^2=m.x(x+1)</script> với \(\Large m\in\

Cho (4x2+4x3)2(4x2+4x+3)2=m.x(x+1) với \(\Large m\in\

4.7/5

Tác giả: Thầy Tùng

Đăng ngày: 18 Aug 2022

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Câu hỏi:

Cho (4x2+4x3)2(4x2+4x+3)2=m.x(x+1) với mR. Chọn câu đúng về giá trị của m.

Đáp án án đúng là: B

Lời giải chi tiết:

(4x2+4x3)2(4x2+4x+3)2=(4x2+4x3+4x2+4x+3)(4x2+4x34x24x3)=(8x2+8x).(6)=8.x(x+1).(6)=48x(x+1)

nên m=48<0