Answer
please see graph
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Work Step by Step
See p. 602, Graphing Complex Numbers
The complex plane is determined by the real axis and the imaginary axis.
To graph the complex number a + bi,
we plot the ordered pair of numbers (a,b) in this plane.
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$z_{1}=2-i$, plot ($2,-1)$
$z_{2}=2+i$, plot ($2,1)$
$z_{1}+z_{2}=2-i+(2+i)=4$
$=4+0i,$ plot ($4,0)$
$z_{1}z_{2}=(2-i)(2+i)$ = difference of squares,
$=2^{2}-i^{2}=4-(-1)=5$
= 5 + 0i, plot ($5,0)$
