Mathematics Help + Small Science

[Tristan]

Please can you help me with these and show how you worked them out if you do? (Thanks):

• Factorise completely and answer:
2a² + a
8x³y² - 4xy³

• Work out the volume of a 4x3x2 cuboid.

• 3.5 = r
pier² = ?

• Make x the subject of the formula and simplify as much as possible:
3x + 2y = 8y - 3

• Trial and improvement for:
x + 1/x = 5
x = ?

• 4.5 = r
pier² = ?

• Dice
Number....|1|2|3|4|5|6
Probability|p|1/6|1/6|1/6|1/6|2/9
Work out p

• Dice thrown twice:

First
4
1/6
<
...
Not 4

Second
4
...
<
...
Not 4

4
...
<
...
Not 4

• From above, what's the probability that a 4 is thrown only once?

• 2x + 3 >(with line under) 1


+Rep to everyone that helps with as many as possible. Please can you have helped me with some by 10:00pm please? Thanks.

Also,
• Find a diagram of a motor, and explain how it works (a simple motor, not a car motor!).

Thanks.

[dirrty]

One rule of this forum is - Do not ask for the answers, which you did.
:]