[tex]\boxed{\underline{\bf \: ANSWER}}[/tex]
[tex] \sf \: ( 5 + 6 i ) ( 5 - 6 i )[/tex]
Multiply complex numbers 5+6i and 5-6i in the same way as you multiply binomials.
[tex] \dashrightarrow \sf 5\times 5+5\times \left(-6i\right)+6i\times 5+6\left(-6\right)i^{2} [/tex]
By definition, i² is -1.
[tex] \dashrightarrow \sf 5\times 5+5\times \left(-6i\right)+6i\times 5+6\left(-6\right)\left(-1\right) [/tex]
Do the multiplications.
[tex] \dashrightarrow \sf \: 25-30i+30i+36 [/tex]
Now cancel -30i & +30i
[tex]\dashrightarrow \sf \: 25 \: \bcancel{- 30i} \: + \: \bcancel{30i}+36 [/tex]
Now the equation becomes
[tex]\dashrightarrow \sf \: 25 \: + 36 \\ \dashrightarrow \boxed{\bf \: 61}[/tex]
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Hope it helps.
ŕάίήвόώşάĻţ2²2²
