Hướng dẫn giải Bài 1 (Trang 135 SGK Toán Giải tích 12)

Bài 1 (Trang 135 SGK Toán Giải tích 12): Thực hiện các phép tính sau: a) (3 - 5i) + (2 + 4i) ; b) (-2 - 3i) + (-1 - 7i) ; c) (4 + 3i) - (5 - 7i) ; d) (2 - 3i) - (5 - 4i) . Hướng dẫn giải: a) <math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mn>3</mn><mo>-</mo><mn>5</mn><mi mathvariant="normal">i</mi></mrow></mfenced><mo>+</mo><mfenced><mrow><mn>2</mn><mo>+</mo><mn>4</mn><mi mathvariant="normal">i</mi></mrow></mfenced><mo>=</mo><mn>5</mn><mo>-</mo><mi mathvariant="normal">i</mi></math> b) <math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mo>-</mo><mn>2</mn><mo>-</mo><mn>3</mn><mi mathvariant="normal">i</mi></mrow></mfenced><mo>+</mo><mfenced><mrow><mo>-</mo><mn>1</mn><mo>-</mo><mn>7</mn><mi mathvariant="normal">i</mi></mrow></mfenced><mo>=</mo><mo>-</mo><mn>3</mn><mo>-</mo><mn>10</mn><mi mathvariant="normal">i</mi></math> c) <math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mn>4</mn><mo>+</mo><mn>3</mn><mi mathvariant="normal">i</mi></mrow></mfenced><mo>-</mo><mo>(</mo><mn>5</mn><mo>-</mo><mn>7</mn><mi mathvariant="normal">i</mi><mo>)</mo><mo>=</mo><mo>-</mo><mn>1</mn><mo>+</mo><mn>10</mn><mi mathvariant="normal">i</mi></math> d) <math xmlns="http://www.w3.org/1998/Math/MathML"><mfenced><mrow><mn>2</mn><mo>-</mo><mn>3</mn><mi mathvariant="normal">i</mi></mrow></mfenced><mo>-</mo><mo>(</mo><mn>5</mn><mo>-</mo><mn>4</mn><mi mathvariant="normal">i</mi><mo>)</mo><mo>=</mo><mo>-</mo><mn>3</mn><mo>+</mo><mi mathvariant="normal">i</mi></math>