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3 years ago

SIMPLIFY (4-74+7) A. 223 B. 9 27 C. 9+2/7 D. 9

Mathematics

1 answer:

sesenic [268]3 years ago

6 0

Answer:

The correct option is D.

Step-by-step explanation:

The given expression is

$(4-\sqrt{7})(4+\sqrt{7})$

Difference of two squares property:

$a^2-b^2=(a+b)(a-b)$

Using the above property, the given expression can be written as

$(4)^2-(\sqrt{7})^2$

Applying square we get

$16-7$

$9$

Therefore the correct option is D.

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How much is 7 inches subtracted by 2/8

lbvjy [14]

That would be 6 and 6/8 inches

4 0

3 years ago

Account A and Account B both have a principal of $2,000 and an annual interest rate of 2%. No additional deposits or withdrawals

GuDViN [60]

Answer:

Account B earns more interest.

After 20 years, account B will have earned $171.89 more.

Step-by-step explanation:

Let's calculate the total for each account.

Account A:

Account A earns simple interest. We know that the principal value is $2000 and the interest rate is 2% or 0.02. We can use the simple interest formula:

$A=P(1+rt)$

Where A is the future value, P is the principal, r is the rate, and t is the time in years.

So, let's substitute 2000 for P, 0.02 for r, and 20 for t. This yields:

$A=2000(1+0.02(20))$

Multiply and add:

$A=2000(1+0.4)=2000(1.4)$

Multiply. So, the total amount of money in Account A after 20 years is:

$A=\$2800$

Since we initially deposited $2000 and our total is now $2800, this means that we earned an interest of $2800-2000=\$ 800$

Account B:

Account B earns compound interest. Like Account A, Account B has a principal value of $2000 and the interest rate is 2% or 0.02. We also know that it's compounded annually, so once per year. We can use the compound interest formula:

$B=P(1+\frac{r}{n}})^{nt}$