# Help with algebra

• Dec 12th 2007, 05:54 AM
sammyfox07
Help with algebra
Could someone please explain and tell me the answer to these questions i would really appreciate it thanxx :)

Q1. Simplify 4xy(cubed)x 3x(squared)y

Q2. Factorise p(squared)-16q(squared)

Ps does anyone know how to get the squared and cubed sign on the keyboard?
• Dec 12th 2007, 06:10 AM
kalagota
Quote:

Originally Posted by sammyfox07
Could someone please explain and tell me the answer to these questions i would really appreciate it thanxx :)

Quote:

Originally Posted by sammyfox07
Q1. Simplify 4xy(cubed)x 3x(squared)y

i cant understand..
Quote:

Originally Posted by sammyfox07
Q2. Factorise p(squared)-16q(squared)

note that $a^2 - b^2 = (a+b)(a-b)$

now, do it with your given.. your given is $p^2 - 16q^2 = p^2 - (4q)^2$

Quote:

Originally Posted by sammyfox07
Ps does anyone know how to get the squared and cubed sign on the keyboard?

group accordingly.. use ^ for power.. or the best thing is, learn LaTex (it is easy).. Ü
• Dec 12th 2007, 06:11 AM
TKHunny
Squared and cubed

There are many ways to do that. The easiest is just to use carefully the symbol "^".

x-squared might be x^2
y-cubed might be y^3

But be careful. Use parentheses to clarify meaning. These are very different:

a^(s+2) and a^s+2

Alternatively, one could learn just a bit of LaTeX.

Rule of thumb, if you use the variable 'x', don't even think of using 'x' to mean multiplication. That is VERY confusing. Dots, parentheses, or simply juxtaposition are quite sufficient.

(4xy^3)(3(x^2)y)

See how I added some parentheses just to make sure it was understood?

Just collect exponents.

(4xy^3)(3(x^2)y) = 4 * x * y^3 * 3 * x^2 * y

This time, I used stars for multiplication and spaces to clarify intent.

(4xy^3)(3(x^2)y) = 4 * x * y^3 * 3 * x^2 * y = 4*3 * x^(1+2) * y^(3+1)

Again, parentheses are used to clarify intent. Do you know where the '1's came from? x = x^1, right?

Finally,

(4xy^3)(3(x^2)y) = 4*3 * x^(1+2) * y^(3+1) = 12(x^3)y^3 = 12(xy)^3