Lunar3lipse
Lunar3lipse Lunar3lipse
  • 02-03-2020
  • Mathematics
contestada

If x+yi/i = 8+ 10i, where x and y are real, what is the value of (x + yi)(x - yi)?
A 164
B 150
C. 75
D. 100

Respuesta :

amna04352
amna04352 amna04352
  • 02-03-2020

Answer:

164

Step-by-step explanation:

(x + iy)/i = 8 + 10i

(x + iy) = (8 + 10i)(i) = 8i + 10i²

= -10 + 8i

(-10 + 8i)(-10 - 8i) = (-10)² + 8² = 164

Answer Link
koyna2001 koyna2001
  • 02-03-2020

Answer:

A.164

Step-by-step explanation:

(x+yi)(x-yi) -> (8+10i)(8-10i)

rule: *(a-b)(a+b)=a^2+b^2

(8+10i)(8-10i) = 64-100i^2

rule: i^2=(-1)

64-100i^2 =  64-100(-1)

=64+100

=164

Answer Link

Otras preguntas

What is f(–3) for the function f(a) = –2a2 – 5a + 4?
-4<3(x+2)-<2 plz help
What is the distance between -23 and 6
the sum of twice a number and 5 is at most 3 less than the number
or inequalities. Greater Than, >, and Less Than, <, mean the solution does NOT contain the number. So would you use and open circle or a closed circle t
Britain profited the most from India by:
find the gcf of 40 and 48
what is 80/9 simplifed
What is it Quartering Act
Which of these statements best describes georgia at the start of the revolutionary war?A)loyalists outnumbered patriots.B)georgia refused to join the war.C)atla