Solve for z
z=-\frac{1}{2}+\frac{7}{2}i=-0.5+3.5i
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z≔-\frac{1}{2}+\frac{7}{2}i
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z=\frac{\left(3+4i\right)\left(1+i\right)}{\left(1-i\right)\left(1+i\right)}
Multiply both numerator and denominator of \frac{3+4i}{1-i} by the complex conjugate of the denominator, 1+i.
z=\frac{\left(3+4i\right)\left(1+i\right)}{1^{2}-i^{2}}
Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}.
z=\frac{\left(3+4i\right)\left(1+i\right)}{2}
By definition, i^{2} is -1. Calculate the denominator.
z=\frac{3\times 1+3i+4i\times 1+4i^{2}}{2}
Multiply complex numbers 3+4i and 1+i like you multiply binomials.
z=\frac{3\times 1+3i+4i\times 1+4\left(-1\right)}{2}
By definition, i^{2} is -1.
z=\frac{3+3i+4i-4}{2}
Do the multiplications in 3\times 1+3i+4i\times 1+4\left(-1\right).
z=\frac{3-4+\left(3+4\right)i}{2}
Combine the real and imaginary parts in 3+3i+4i-4.
z=\frac{-1+7i}{2}
Do the additions in 3-4+\left(3+4\right)i.
z=-\frac{1}{2}+\frac{7}{2}i
Divide -1+7i by 2 to get -\frac{1}{2}+\frac{7}{2}i.
Examples
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y = 3x + 4
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Matrix
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Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
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Limits
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