Evaluate
-6-8i
Real Part
-6
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1\times 2+1\times \left(-4i\right)-2i\times 2-2\left(-4\right)i^{2}
Multiply complex numbers 1-2i and 2-4i like you multiply binomials.
1\times 2+1\times \left(-4i\right)-2i\times 2-2\left(-4\right)\left(-1\right)
By definition, i^{2} is -1.
2-4i-4i-8
Do the multiplications.
2-8+\left(-4-4\right)i
Combine the real and imaginary parts.
-6-8i
Do the additions.
Re(1\times 2+1\times \left(-4i\right)-2i\times 2-2\left(-4\right)i^{2})
Multiply complex numbers 1-2i and 2-4i like you multiply binomials.
Re(1\times 2+1\times \left(-4i\right)-2i\times 2-2\left(-4\right)\left(-1\right))
By definition, i^{2} is -1.
Re(2-4i-4i-8)
Do the multiplications in 1\times 2+1\times \left(-4i\right)-2i\times 2-2\left(-4\right)\left(-1\right).
Re(2-8+\left(-4-4\right)i)
Combine the real and imaginary parts in 2-4i-4i-8.
Re(-6-8i)
Do the additions in 2-8+\left(-4-4\right)i.
-6
The real part of -6-8i is -6.
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