Evaluate
15+10i
Real Part
15
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5i\times 2+5\left(-3\right)i^{2}
Multiply 5i times 2-3i.
5i\times 2+5\left(-3\right)\left(-1\right)
By definition, i^{2} is -1.
15+10i
Do the multiplications. Reorder the terms.
Re(5i\times 2+5\left(-3\right)i^{2})
Multiply 5i times 2-3i.
Re(5i\times 2+5\left(-3\right)\left(-1\right))
By definition, i^{2} is -1.
Re(15+10i)
Do the multiplications in 5i\times 2+5\left(-3\right)\left(-1\right). Reorder the terms.
15
The real part of 15+10i is 15.
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