Evaluate
-80+55i
Real Part
-80
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-9\times 8-9i+8i\times 8+8i^{2}
Multiply complex numbers -9+8i and 8+i like you multiply binomials.
-9\times 8-9i+8i\times 8+8\left(-1\right)
By definition, i^{2} is -1.
-72-9i+64i-8
Do the multiplications.
-72-8+\left(-9+64\right)i
Combine the real and imaginary parts.
-80+55i
Do the additions.
Re(-9\times 8-9i+8i\times 8+8i^{2})
Multiply complex numbers -9+8i and 8+i like you multiply binomials.
Re(-9\times 8-9i+8i\times 8+8\left(-1\right))
By definition, i^{2} is -1.
Re(-72-9i+64i-8)
Do the multiplications in -9\times 8-9i+8i\times 8+8\left(-1\right).
Re(-72-8+\left(-9+64\right)i)
Combine the real and imaginary parts in -72-9i+64i-8.
Re(-80+55i)
Do the additions in -72-8+\left(-9+64\right)i.
-80
The real part of -80+55i is -80.
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Limits
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