Evaluate
6-7i
Real Part
6
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1\times 2+i-4i\times 2-4i^{2}
Multiply complex numbers 1-4i and 2+i like you multiply binomials.
1\times 2+i-4i\times 2-4\left(-1\right)
By definition, i^{2} is -1.
2+i-8i+4
Do the multiplications.
2+4+\left(1-8\right)i
Combine the real and imaginary parts.
6-7i
Do the additions.
Re(1\times 2+i-4i\times 2-4i^{2})
Multiply complex numbers 1-4i and 2+i like you multiply binomials.
Re(1\times 2+i-4i\times 2-4\left(-1\right))
By definition, i^{2} is -1.
Re(2+i-8i+4)
Do the multiplications in 1\times 2+i-4i\times 2-4\left(-1\right).
Re(2+4+\left(1-8\right)i)
Combine the real and imaginary parts in 2+i-8i+4.
Re(6-7i)
Do the additions in 2+4+\left(1-8\right)i.
6
The real part of 6-7i is 6.
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