• Jan 14th 2010, 09:21 PM
iDrum
Please help, I'm in trig and we are reviewing algebra, having a hard time remembering how to do some of this stuff. Thank you!

Factor Completely if possible:

8.) me + mi + my

Solve each equation for x:

48.) (2x-3)(2x-3) = 4

52.) a.) 12x^2 - 5x -3 = 0
b.) 30x^2 + 13x -10 = 0
• Jan 14th 2010, 09:33 PM
pickslides
Quote:

Originally Posted by iDrum

Factor Completely if possible:

8.) me + mi + my

Take out $m$ as a common factor

Spoiler:
$m(e + i + y)$

Quote:

Originally Posted by iDrum

Solve each equation for x:

48.) (2x-3)(2x-3) = 4

52.) a.) 12x^2 - 5x -3 = 0
b.) 30x^2 + 13x -10 = 0

Exapnd the first equation to find the form $ax^2+bx+c=0$

Then for that and the other 2 use

$
x= \frac{-b\pm\sqrt{b^2-4ac}}{2a}
$
• Jan 14th 2010, 10:19 PM
Hello iDrum
Quote:

Originally Posted by iDrum
...
Solve each equation for x:

48.) (2x-3)(2x-3) = 4

Write this as:
$(2x-3)^2=4$
and then take square roots, not forgetting the $\pm$ sign on the right:
$2x-3=\pm2$

$\Rightarrow 2x = 3+2$ or $3-2$

$\Rightarrow x = 2.5$ or $0.5$
Quote:

52.) a.) 12x^2 - 5x -3 = 0
$12x^2 - 5x -3 = 0$

$\Rightarrow(3x+1)(4x-3)=0$

Can you complete it?
Quote:

b.) 30x^2 + 13x -10 = 0
This won't factorise, so use the formula:
$x=\frac{-13\pm\sqrt{13^2-4(30)(-10)}}{60}$
Can you complete it?