Bereken
- \((-4-9i)+(-7-6i)\)
- \((+3i) \cdot (9-6i)\)
- \((8-3i) \cdot (4+5i)\)
- \(\frac{6+i}{6+7i}\)
- \((-10+i)-(-7+7i)\)
- \((-3+4i)-(-3+7i)\)
- \((-7i) \cdot (-7+8i)\)
- \((5+7i)-(8-2i)\)
- \((7+6i)-(-8+i)\)
- \(\frac{-6+5i}{-3+6i}\)
- \((3-8i) \cdot (2-7i)\)
- \((9-4i)+(6-3i)\)
Bereken
Verbetersleutel
- \((-4-9i)+(-7-6i)= -4-9i -7-6i =\color{red}{-4-7}\color{blue}{-9i -6i}=\color{red}{-11}\color{blue}{-15i}\)
- \((+3i) \cdot (9-6i)= +27 i-18i^2 = \color{red}{18}\color{blue}{+27i}\)
- \((8-3i) \cdot (4+5i)= 32+40i -12 i-15i^2 = 32+40i -12 i+15= \color{red}{32+15}\color{blue}{+40i -12i}=\color{red}{47}\color{blue}{+28i}\)
- \(\frac{6+i}{6+7i}= \frac{6+i}{6+7i} \cdot \frac{6-7i}{6-7i} = \frac{36-42i +6 i-7i^2 }{(6)^2-(7i)^2} = \frac{36-42i +6 i+7}{36 + 49} = \frac{43-36i }{85} = \frac{43}{85} + \frac{-36}{85}i \)
- \((-10+i)-(-7+7i)= -10+i +7-7i =\color{red}{-10+7}\color{blue}{+i -7i}=\color{red}{-3}\color{blue}{-6i}\)
- \((-3+4i)-(-3+7i)= -3+4i +3-7i =\color{red}{-3+3}\color{blue}{+4i -7i}=\color{blue}{-3i}\)
- \((-7i) \cdot (-7+8i)= +49 i-56i^2 = \color{red}{56}\color{blue}{+49i}\)
- \((5+7i)-(8-2i)= 5+7i -8+2i =\color{red}{5-8}\color{blue}{+7i +2i}=\color{red}{-3}\color{blue}{+9i}\)
- \((7+6i)-(-8+i)= 7+6i +8-i =\color{red}{7+8}\color{blue}{+6i -i}=\color{red}{15}\color{blue}{+5i}\)
- \(\frac{-6+5i}{-3+6i}= \frac{-6+5i}{-3+6i} \cdot \frac{-3-6i}{-3-6i} = \frac{18+36i -15 i-30i^2 }{(-3)^2-(6i)^2} = \frac{18+36i -15 i+30}{9 + 36} = \frac{48+21i }{45} = \frac{16}{15} - \frac{-7}{15}i \)
- \((3-8i) \cdot (2-7i)= 6-21i -16 i+56i^2 = 6-21i -16 i-56= \color{red}{6-56}\color{blue}{-21i -16i}=\color{red}{-50}\color{blue}{-37i}\)
- \((9-4i)+(6-3i)= 9-4i +6-3i =\color{red}{9+6}\color{blue}{-4i -3i}=\color{red}{15}\color{blue}{-7i}\)