On the 1st Jan 2012 Beth invested some money into a bank account.

1 answer:

7 0

Account on 2014 is £17,466 when multipliled by 0.025 (interest per year) it will result to £436.65. So the money she had excluding the interest of the said year is £17,029.35 (17,466 - 436.65).
Going back to 2013, she withdraws £1000. If she has £17,029.35 in 2014, we can add £1000 to get £18, 029.35.If we take 2.5% from £18, 029.35. (18,029.35. x 0.025) the result is £450.73. Excluding the interest of year 2013, the money amounts to £17,578.62 (18,029.35 - 450.73), which is the original invested amount on her bank account from year 2012.

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On Monday, during a one day sale, the price of a suit was decreased by 20%. On Tuesday, the price of the suit was changed back t

nignag [31]

Answer:

25%

Step-by-step explanation:

If we consider the original price of the piece of suit is x.

Given that, on Monday during a one day sale, the price of the suit was decreased by 20%.

Therefore, the new price of the suit on Monday is $x( 1 - \frac{20}{100}) = 0.8x$ .

Now, the price of the suit on Tuesday was changed back to the original price i.e. x.

Therefore, the price is increase by (x - 0.8x) = 0.2x from the price of 0.8x.

So, the percentage change in price of the suit on Tuesday is $\frac{0.2x}{0.8x} \times 100 = 25$ %. (Answer)

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3 years ago

Prove that.....cos^2α(cosec^2α-cot^2α)=cos^2α

Dafna1 [17]

Step-by-step explanation:

We must prove that

cos²a(csc²a-cot²a) = cos²a

If we look at both sides, we can see that we have cos²a * something = cos²a. Therefore, if we can get that something to equal 1, we have our proof. In this case, that something is csc²a-cot²a. Using this information, we can work from within the parenthesis and go from there.

We can start by expanding the items in the parenthesis. Taking that csc(x) = 1/sin(x) and cot(a) = cos(x)/sin(x), we can say that

cos²a(csc²a-cot²a) = cos²a(1/sin²a - cos²a/sin²a). Because both items in the parenthesis have a denominator of sin²a, we can subtract cos²a from 1 to get

cos²a(1/sin²a - cos²a/sin²a)= cos²a((1-cos²a)/sin²a))

Next, we know that cos²a+sin²a=1, so 1-cos²a = sin²a. Plugging that in, we get

cos²a((1-cos²a)/sin²a)) = cos²a(sin²a/sin²a)

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3 years ago

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Aleks [24]

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Your question is $x^2-2x-8=0$

So $a=1 \\b=-2\\c=-8$

So plug in your numbers:
$x= \frac{-(-2)\pm \sqrt{(-2)^2-4(1)(-8)} }{2(1)}$

Simplify:
$x= \frac{2\pm \sqrt{4-(-32)} }{2}$

Simplify a little more:
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So $x=4, x=-2$