Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**Liam****Guest**

Im stuck! Wotz 7(5-2e)??????? I have no Idea whatsoever! Whoever helps me gets a pat on the back!

**Roraborealis****Member**- Registered: 2005-03-17
- Posts: 1,594

It just so happens that algebra is my speciality.

OK, Liam, you should know that when you say something like 7b+2, that is simply 7b's and a positIve two, just stuck together like that. But when you have the brackets, it gets more difficult.

7(5-2e), you say. Well, a number outside a bracket just means that 'this is how many of these we have.' So, in this case, it means 7 '5-2e's.

That can be simplified down into 35-14e (multiplied it all by seven). Multiply the positive fives first, then the minus two e's by seven, and that's what you get.

That's your answer, as you can't get any further.

School is practice for the future. Practice makes perfect. But - nobody's perfect, so why practice?

Offline

**Polly****Member**- Registered: 2005-06-24
- Posts: 221

Hi liam i don't get algebra too

Offline

**Roraborealis****Member**- Registered: 2005-03-17
- Posts: 1,594

It's really easy once you put the right effort into it.

School is practice for the future. Practice makes perfect. But - nobody's perfect, so why practice?

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 17,004

Algebra is a very useful tool in mathematics.

There are some basic rules you got to remember,

and if you do, you are good at it!

Like if you got to solve this problem,

knowledge of elementary algebra really helps!

Problem :- Ten years ago, my dad was four times my age.

Ten years later, he'd be double my age.

By how many years is he elder to me?

Character is who you are when no one is looking.

Offline

**laureneh****Member**- Registered: 2005-06-28
- Posts: 15

english is wew beta;);)

Offline

**mathsyperson****Moderator**- Registered: 2005-06-22
- Posts: 4,900

Ten years ago, he'd be 4 times my age.

In an algebraic form: 4(Me-10)=Dad-10

Multiply out the brackets: 4Me-40=Dad-10

Add 10: 4Me-30=Dad

Ten years later, he'd be double my age.

In an algebraic form: 2(Me+10)=Dad+10

Multiply out: 2Me+20=Dad+10

Take away 10: 2Me+10=Dad

Substitute: 4Me-30=2Me+10

Simplify: 2Me=40

Solve: Me=20

Substitute to find Dad: (4x20)-30=(2x20)+10=50

Dad is 50-20=30 years elder to me.

Why did the vector cross the road?

It wanted to be normal.

Offline

Pages: **1**