Answer:
i) 28 - 30i
ii) 36 + 28i
Step-by-step explanation:
i) x = 6 + i ⇒2x = 2(6 + i) = 12 + 2i
z = 4 - 8i ⇒ 4z = 4(4 - 8i) = 16 - 32i
2x + 4z = (12 + 2i) + (16 - 32i) = 28 - 30i
ii) w = -1 + 5i and z = 4 - 8i
w × z = (-1 + 5i)(4 - 8i) = -4 + 8i + 20i - 40
⇒collect like terms
w × z = -4 + 28i - 40
∵ 
∴w × z = -4 + 28i - 40(-1) = -4 + 28i + 40 = 36 + 28i
Answer:

And we can use the following formula:

And replacing the info we got:

Step-by-step explanation:
We define two events for this case A and B. And we know the probability for each individual event given by the problem:


And we want to find the probability that A and B both occurs if A and B are independent events, who menas the following conditions:


And for this special case we want to find this probability:

And we can use the following formula:

And replacing the info we got:

Answer:
$1.25f + $0.75f
Step-by-step explanation:
The cost of one bagel is $1.25 and cream cheese costs $0.75 per person. The total amount Jack and Jenn will spend on breakfast depends on the number of friends that eat breakfast.
to get the total amount spent on breakfast, multiply the cost of bagel by the number of friends and the cost of cream cheese by the number of friends. Add these numbers
The total amount spent on food = $1.25f + $0.75f
The decimal conversion to 8 39/40 is 8.975 and the decimal terminates.