The price of a ring was increased by 9% to £1800. What was the price before the increase? Give your answer to the nearest penny.

Mathematics

2 answers:

Alla [95]3 years ago

6 0

Answer:

see steps

Step-by-step explanation:

New price was increase from 100% to 109% at £1800.

By proportionality,

old price / 100% = 1800 / 109%

Cross multiply to get

old price = $1800 * 100% / 109% = £1651.38

Firlakuza [10]3 years ago

4 0

I do not know just need answers really hard questions

You might be interested in

train traveling with 100 cars all cars are exact size. the cars are 20 ft long 10ft wide and 10ft tall. how much available volum

jeyben [28]

Find the volume of 1 car by multiplying the length by the width by the height:

Volume of 1 car = 20 x 10 x 10 = 2000 cubic feet.

Now multiply the volume of 1 car by the total number of cars:

2000 x 100 = 200,000 cubic feet total.

3 0

3 years ago

Integrate e^x(sin(x) cos(x))

Karo-lina-s [1.5K]

$I=\int e^x(\sin(x)\cos(x))dx=\int e^x(\frac{1}{2}\sin(2x))dx=\frac{1}{2}\int e^x\sin(2x)dx$

$\text{If }u=\sin(2x)\to du=2\cos(2x)dx~\text{and}~dv=e^xdx\to v=e^x:\\\\
\text{Using }\int u\,dv=uv-\int v\,du:\\\\
I=\frac{1}{2}(e^x\sin(2x)-\int e^x(2\cos(2x))dx)\\\\
2I=e^x\sin(2x)-2\underbrace{\int e^x\cos(2x)dx}_{I_2}$

Looking for $I_2$ :

$\text{If}~u=\cos(2x)\to du=-2\sin(2x)dx~\text{and}~dv=e^xdx\to v=e^x:\\\\
I_2=e^x\cos(2x)-\int e^x(-2\sin(2x))dx\\\\ I_2=e^x\cos(2x)+2\int e^x(\sin(2x))dx\\\\ I_2=e^x\cos(2x)+2\int e^x(2\sin(x)\cos(x))dx\\\\ I_2=e^x\cos(2x)+4\int e^x(\sin(x)\cos(x))dx=e^x\cos(2x)+4I$

Replacing:

$2I=e^x\sin(2x)-2I_2\iff\\\\2I=e^x\sin(2x)-2(e^x\cos(2x)+4I)\iff\\\\
2I=e^x\sin(2x)-2e^x\cos(2x)-8I\iff\\\\
10I=e^x\sin(2x)-2e^x\cos(2x)\iff\\\\
I=\dfrac{e^x}{10}(\sin(2x)-2\cos(2x))\\\\
\boxed{\int e^x(\sin(x)\cos(x))dx=\dfrac{e^x}{10}(\sin(2x)-2\cos(2x))+C}$

6 0

3 years ago

Numbers Of pizza to order <br> What is the slope of the line

Tanzania [10]

U can order 1 pizza lol

3 0

3 years ago

Read 2 more answers

What percent of the medium T-shirts are black? Round to the nearest percent.

Art [367]

The answer would be about 23% I hope this helps

3 0