Thread: [SOLVED] Expanding brackets and Simplyfying

1. [SOLVED] Expanding brackets and Simplyfying

How can I simplyfy this:

4x(x+3)+4x2+x

and this:

c2 X 4cb

and this:

-9z(z3 - 4z+5)

Thank you!!!!!!!!!!!!

2. Originally Posted by Shandy
How can I simplyfy this:

4x(x+3)+4x2+x

and this:

c2 X 4cb

and this:

-9z(z3 - 4z+5)

Thank you!!!!!!!!!!!!
$\displaystyle 4x(x+3) + 4x^2 + x$

Multiply:

$\displaystyle 4x^2 + 12x + 4x^2 + x$

$\displaystyle 8x^2 + 13x$

Factor:

$\displaystyle x(8x+13)$

-----------------------------

c2 X 4cb <------ You need to clarify this.

-----------------------------

$\displaystyle -9z(z^3 - 4z+5)$

Multiply:

$\displaystyle -9z^4 + 36z^2 - 45z$

Factor:

$\displaystyle -z(9z^3 - 36z + 45)$

3. Originally Posted by Shandy
How can I simplyfy this:

4x(x+3)+4x2+x

and this:

c2 X 4cb

and this:

-9z(z3 - 4z+5)

Thank you!!!!!!!!!!!!
Hi Shandy,

Distribute the 4x in the first one and then combine like terms.

$\displaystyle 4x(x+3)+4x^2+x=4x^2+12x+4x^2+x=8x^2+13x$

In the second one,

$\displaystyle c^2 \cdot 4cb=4c^3b$

And the third one,

$\displaystyle -9z(z^3 - 4z+5)=-9z^4+36z^2-45z$

Remember the rule $\displaystyle a^m \cdot a^n=a^{m+n}$