Evaluate
45+9i
Real Part
45
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9i\times 1+9\left(-5\right)i^{2}
Multiply 9i times 1-5i.
9i\times 1+9\left(-5\right)\left(-1\right)
By definition, i^{2} is -1.
45+9i
Do the multiplications. Reorder the terms.
Re(9i\times 1+9\left(-5\right)i^{2})
Multiply 9i times 1-5i.
Re(9i\times 1+9\left(-5\right)\left(-1\right))
By definition, i^{2} is -1.
Re(45+9i)
Do the multiplications in 9i\times 1+9\left(-5\right)\left(-1\right). Reorder the terms.
45
The real part of 45+9i is 45.
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