Hướng dẫn giải Hoạt động 1 (Trang 55 SGK Toán Đại số & Giải tích 11)
<p><strong class="content_question">Đề bài</strong></p>
<p>Khai triển biểu thức <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mfenced><mrow><mi>a</mi><mo>+</mo><mi>b</mi></mrow></mfenced><mn>4</mn></msup></math> thành tổng các đơn thức.</p>
<p><strong class="content_detail">Lời giải chi tiết</strong></p>
<p><math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mfenced><mrow><mi>a</mi><mo>+</mo><mi>b</mi></mrow></mfenced><mn>4</mn></msup><mo>=</mo><msup><mfenced><mrow><mi>a</mi><mo>+</mo><mi>b</mi></mrow></mfenced><mn>3</mn></msup><mfenced><mrow><mi>a</mi><mo>+</mo><mi>b</mi></mrow></mfenced><mspace linebreak="newline"/><mo>=</mo><mfenced><mrow><msup><mi>a</mi><mn>3</mn></msup><mo>+</mo><mn>3</mn><msup><mi>a</mi><mn>2</mn></msup><mi>b</mi><mo>+</mo><mn>3</mn><mi>a</mi><msup><mi>b</mi><mn>2</mn></msup><mo>+</mo><msup><mi>b</mi><mn>3</mn></msup></mrow></mfenced><mfenced><mrow><mi>a</mi><mo>+</mo><mi>b</mi></mrow></mfenced><mspace linebreak="newline"/><mo>=</mo><msup><mi>a</mi><mn>4</mn></msup><mo>+</mo><mn>3</mn><msup><mi>a</mi><mn>3</mn></msup><mi>b</mi><mo>+</mo><mn>3</mn><msup><mi>a</mi><mn>2</mn></msup><msup><mi>b</mi><mn>2</mn></msup><mo>+</mo><mi>a</mi><msup><mi>b</mi><mn>3</mn></msup><mo>+</mo><msup><mi>a</mi><mn>3</mn></msup><mi>b</mi><mo>+</mo><mn>3</mn><msup><mi>a</mi><mn>2</mn></msup><msup><mi>b</mi><mn>2</mn></msup><mo>+</mo><mn>3</mn><mi>a</mi><msup><mi>b</mi><mn>3</mn></msup><mo>+</mo><msup><mi>b</mi><mn>4</mn></msup><mspace linebreak="newline"/><mo>=</mo><msup><mi>a</mi><mn>4</mn></msup><mo>+</mo><mn>4</mn><msup><mi>a</mi><mn>3</mn></msup><mi>b</mi><mo>+</mo><mn>6</mn><msup><mi>a</mi><mn>2</mn></msup><msup><mi>b</mi><mn>2</mn></msup><mo>+</mo><mn>4</mn><mi>a</mi><msup><mi>b</mi><mn>3</mn></msup><mo>+</mo><msup><mi>b</mi><mn>4</mn></msup></math><br /><br /></p>