Answer is C, just multiply and expand.
Answer:
x = 4 and y = - 5
Step-by-step explanation:
note that the product of a complex number and it's conjugate is real
That is
(a + bi)(a - bi) where a, b are real
= a² - abi + abi - b²i²
= a² + b² ← a real number
For (4 + 5i)(x + yi) to be real
we require (x + yi) to be the conjugate of 4 + 5i , that is 4 - 5i
(4 + 5i)(4 - 5i) ⇒ x = 4 and y = - 5
Uh do you mean he earned $225 per week?
If yes, then he earned 45 per day.
Step-by-step explanation:
Step 1: Multiply the 2 with the X to get 2X.
Step 2: multiply the 2 with the 4 and get 8
Step 3: your answer is 2X+8
Answer:
(-1, 5)
Step-by-step explanation:
3 [x + y = 4]
3x + 3y = 12
- 3x + 7y = 32
-4y = -20
y = 5
x + 5 = 4
x = -1
