Multiply then add and then subtract
9514 1404 393
Answer:
- interest: $63
- balance: $9063
Step-by-step explanation:
After 6 months, the interest accrued is ...
I = Prt
I = $9000·0.014·(6/12) = $63
This is added to the principal to get the balance at that point in time.
$9000 +63 = $9063
__
The interest earned in the first 6 months is $63. The balance after 6 months is $9063.
_____
The compound interest formula will give you the same result for one compounding period. It tells you the balance is ...
A = P(1 +r/n)^(nt)
where n is the number of times interest is compounded in a year (2), and t is the number of years (1/2). For annual rate r = 1.4%, this is ...
A = $9000(1 +0.007)^(2×1/2) = $9000·1.007 = $9063
Answer:
Step-by-step explanation:
The vertex and focus are horizon aligned, so the parabola is horizontal and the directrix is a vertical line.
The vertex is halfway between focus and directrix. Directrix: x = -4
The two planes are flying on the two legs of a right triangle.
The straight distance between them is the hypotenuse of the triangle.
Since the speeds are in mph, let's work the time in hours.
Call the time 'H' that we're looking for.
It's the number of hours after they both take off that they're 650 miles apart.
After 'H' hours, the first plane has gone 500H miles north.
After 'H' hours, the second plane has gone 1200H miles east.
After 'H' hours, they are 650 miles apart.
Do you remember this for a right triangle ? ==> A² + B² = C²
(500H)² + (1200H)² = (650)²
250,000H² + 1,440,000H² = 422,500
1,690,000 H² = 422,500
H² = (422,500) / (1,690,000) = 0.25
H = √0.25 = 1/2 hour = 30 minutes
