Thursday

November 27, 2014

November 27, 2014

Posted by **asdf** on Friday, December 31, 2010 at 4:08am.

2x^2 - 10x

=2(x^2 - 5x)

=2{[x-(5/2)]^2 - [(5/2)^2]}

=2[x-(5/2)]^2 - (25/2)

Why isn't (5/2)^2 (25/4)?

I'm struggling with the exercises as well.

3x^2 - 24x

I get 3(x-4)^2 - 16 or if I try to follow the example, 3(x-4)^2 - 32, but the answer at the back of the book is 3(x-4)^2 - 48

- Math; Complete the square for the expressions -
**asdf**, Friday, December 31, 2010 at 4:10amI meant, "Why isn't (25/2)^2 (25/4)?"

- Math; Complete the square for the expressions -
**drwls**, Friday, December 31, 2010 at 7:09amYou seem to have forgotten a basic rule of multiplying fractions.

a/b * c/d = ac/(bd)

The square of any fraction a/b is a^2/b^2.

For example, 2/3 of 2/3 = (2/3)^2 = 4/9

and (25/2)^2 = 625/4

Looking at your second problem,

3x^2 - 24x

= 3(x^2 -8x) Now add and subtract 48

= 3(x^2 -8x +16) -48

= 3(x-4)^2 -48

**Answer this Question**

**Related Questions**

Fib. Number - I noticed someone else is having problems with the same problem ...

College Math II - Show a complete solution to each problem. Find the exact ...

Math Homework - 1) Given the side of a square pyramid is 6cm and the altitude is...

College Algebra - I need some help with a handful of questions. I need to see ...

College Algebra - I need some help with a handful of questions. I need to see ...

College Algebra help please - I need some help with a handful of questions. I ...

Algebra 2 - could you walk me thorugh these problems simplfy square root 18 - 3 ...

Math - Having a problem writing an expanded number in notation in descending ...

3rd grade - Good evening ~ I have 2 questions. Kelsey was assigned math homework...

Math Algebra 1 - i was wondering if anyone could help me on this problem. expand...