Evaluate
28-3i
Real Part
28
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2\times 5+2\times \left(6i\right)-3i\times 5-3\times 6i^{2}
Multiply complex numbers 2-3i and 5+6i like you multiply binomials.
2\times 5+2\times \left(6i\right)-3i\times 5-3\times 6\left(-1\right)
By definition, i^{2} is -1.
10+12i-15i+18
Do the multiplications.
10+18+\left(12-15\right)i
Combine the real and imaginary parts.
28-3i
Do the additions.
Re(2\times 5+2\times \left(6i\right)-3i\times 5-3\times 6i^{2})
Multiply complex numbers 2-3i and 5+6i like you multiply binomials.
Re(2\times 5+2\times \left(6i\right)-3i\times 5-3\times 6\left(-1\right))
By definition, i^{2} is -1.
Re(10+12i-15i+18)
Do the multiplications in 2\times 5+2\times \left(6i\right)-3i\times 5-3\times 6\left(-1\right).
Re(10+18+\left(12-15\right)i)
Combine the real and imaginary parts in 10+12i-15i+18.
Re(28-3i)
Do the additions in 10+18+\left(12-15\right)i.
28
The real part of 28-3i is 28.
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