Evaluate
19-13i
Real Part
19
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5\times 2+5i-9i\times 2-9i^{2}
Multiply complex numbers 5-9i and 2+i like you multiply binomials.
5\times 2+5i-9i\times 2-9\left(-1\right)
By definition, i^{2} is -1.
10+5i-18i+9
Do the multiplications.
10+9+\left(5-18\right)i
Combine the real and imaginary parts.
19-13i
Do the additions.
Re(5\times 2+5i-9i\times 2-9i^{2})
Multiply complex numbers 5-9i and 2+i like you multiply binomials.
Re(5\times 2+5i-9i\times 2-9\left(-1\right))
By definition, i^{2} is -1.
Re(10+5i-18i+9)
Do the multiplications in 5\times 2+5i-9i\times 2-9\left(-1\right).
Re(10+9+\left(5-18\right)i)
Combine the real and imaginary parts in 10+5i-18i+9.
Re(19-13i)
Do the additions in 10+9+\left(5-18\right)i.
19
The real part of 19-13i is 19.
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Limits
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