Sau 18 tháng, số tiền nợ cả gốc lẫn lãi phải trả là $5200. Số tiền gốc là bao nhiêu nếu lãi suất đơn là 8%/năm?

I dont understand please help

DiKsa [7]

$2 \frac{1}{2}+(-2\frac{1}{4})$

This is equal to:

$2\frac{1}{2}-2\frac{1}{4}$

When you add a negative number, it turns into subtraction.

First, I would change it to mixed numbers:

$\frac{5}{2}-\frac{9}{4}$

Now, you need to change the denominators to make sure they are the same on both fractions. I changed the first fraction's denominator to 4 so they match. You can do this by multiplying the numerator by 2:

$\frac{10}{4}-\frac{9}{4}$

Now, you simply subtract:

10-9=1

1/4 is your answer.

I hope this helps :)

3 0

3 years ago

PLEASE HELP PLEASE PLEASE

Maslowich

Answer:

quadratic

Step-by-step explanation:

The x-values are sequential, so we can look at the y-values.

Differences from one to the next are ...

-7, -1, 5, 11, 17

And the differences of these numbers are ...

6, 6, 6, 6

When second differences are constant, the sequence can be produced by a second-degree (quadratic) polynomial.

__

Here, that polynomial is ...

y = 3x² +2x -1

The regression functions of a graphing calculator can help you find the appropriate formula.

6 0

3 years ago

One pipe can empty a tank 5 times faster than another pipe can fill the tank. Starting with a full tank, if both pipes are turne

xxTIMURxx [149]

Answer:

40 hours

Step-by-step explanation:

Let's say that the slower pipe can fill x amount of the tank in one hour. It adds x amount to the tank every hour. Therefore, we can say, for the slower pipe,

1 hour = x amount

Then, the faster pipe empties the tank 5 times faster than the slower pipe fills it, so it removes 5 times the amount that the smaller pipe puts in, so for the faster pipe,

1 hour = -5x amount (negative to symbolize removing).

For the problem at hand, the tank starts at full, or 100%=1. It ends empty, or at 0% = 0. After 10 hours, if we only account for the slower pipe, we add x amount to the tank every hour, so we add 10 times that total, resulting in

1 + 10 * x as the ending result if we don't include the faster pipe. Then, the faster pipe removes 5x every hour, so in 10 hours, it removes 50x, so we have

1+10 * x - 50 * x as the final amount of stuff in the tank, which is equal to 0. Therefore, we have

1 + 10 * x - 50 * x = 0

1 - 40 * x = 0

add 40*x to both sides to isolate the x and its coefficient

1 = 40 * x

divide both sides by 40 to isolate x

x= 0.025

Therefore, the slower pipe adds 0.025, or 1/40 = 2.5% to the tank every hour. We want to figure out how long it would take for the slower pipe to fill up an empty tank, or turn it from 0% to 100% full.

Because the slower pipe adds 2.5% of the tank every hour, we can say that over y hours, it fills up

2.5% * y amount of the tank. We want to figure out how many hours it would take to make it 100% (we need to add 100% of the tank in the problem), so we can say

2.5% * y = 100%

divide both sides by 2.5% to isolate y

100%/2.5% = y = 40

5 0

3 years ago

Use the grouping method to factor this polynomial completely. 3x3 + 12x2 + 2x + 8

dezoksy [38]

Answer:

(3x^2 + 2)(x + 4).

Step-by-step explanation:

3x3 + 12x2 + 2x + 8

3x^2(x + 4) + 2(x + 4) The x + 4 is common to the 2 groups so we have:

(3x^2 + 2)(x + 4).

3 0

3 years ago

The superintendent of a school district wanted to predict the percentage of students passing a sixth-grade proficiency test. she

Orlov [11]

Answer:

B. H1= b1=0

Step-by-step explanation:

the alternative hypothesis is correct

7 0

3 years ago