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Salut!

We know that the total surface area of cylinder B is 4 times that of cylinder A.

Knowing this, you can conclude that the area ratio k² is 4, where A is the initial shape and B is the image shape.

k² = Area B / Area A

4 = Area B / Area A

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So you can find the similarity ratio k from the area ratio k². Then, you know that the height of cylinder A is 20 cm. Therefore, you can calculate the height of cylinder B, since you know the similarity ratio.

Here are some pages that might help you:

• The Similarity Ratio for Lengths, Areas, and Volume (k, k², k³) | Secondaire | Alloprof
• The Area and the Volume of Solids | Secondaire | Alloprof
• Units of Capacity and Their Conversion | Secondaire | Alloprof

I'll let you continue with these clues. If you have any other questions, we're here! :)

Hi!

You have:

$$4a^2-9$$

You can use the difference of squares technique to find the factors of this expression:

$$(2a)^2-3^2$$

$$(2a-3)(2a+3)

So the factors are (2a-3) and (2a+3). The sum of these factors is:

$$(2a-3)+(2a+3)$$

$$2a-3+2a+3$$

I'll let you do the maths ;)

Reach out if there is anything else! 😁

Hi!

You can use the quadratic formula to find the answer(s) to this equation:

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Try to do the math and let us know if you can't find the answer! :)

Hi!

You have :

$$(2x+1)^2-64$$

You can rewrite the expression like this:

$$(2x+1)^2-8^2$$

Then, you can use the difference of squares technique!

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I'll let you do the factoring with this clue :)

Hi!

You have the expression:

$$(x+4)² + (2x-3)(x+4)$$

You can rewrite it like this:

$$(x+4)(x+4) + (2x-3)(x+4)$$

Now you can factor (x+4):

$$(x+4)[(x+4) + (2x-3)]$$

Then simplify the big parenthesis:

$$(x+4)(x+4 + 2x-3)$$

$$(x+4)(3x+1)$$

There you go! :D