Posted by **Micha** on Monday, October 1, 2007 at 12:35am.

How do I work this correctly? I know the answer is 7 but I am doing something wrong.Here is what I have...

x+(2x-5)=10

x+(2x-5)^2=10^2

x+2x-5=100

3x-5+5=100+5

3x=105

x=35

PLEASE HELP!

- Algebra -
**Nick**, Monday, October 1, 2007 at 12:55am
what is the a~ all about? If it is a square root symbol then the solution looks like this:

x + (2x-5)^(1/2) = 10 : move x to other side

(2x-5)^(1/2) = 10 - x : square both sides

2x-5 = (10-x)^2 : expand the squared term

2x-5 = 100-10x-10x+x^2 : combine terms

0 = 105 - 22x + x^2 : use quadratic formula to solve for x

x =[-(-22) +/- sqrt(22^2 -4*1*105)]/(2*1)

x= [22 +/- sqrt(484 - 420)]/2

x= [22 +/- 8] / 2

x= 7 or 15

Plugging back into our initial equation shows that 7 is a solution, but 15 is not. This is because we started with a square root, which is invalid for negative numbers.

Regards.

## Answer this Question

## Related Questions

- 8th Grade Algebra: Answer Check - Find the length of the 3rd side of each right ...
- Math - Solve the equation: 4x^2 + 100 = 0 Here is my work: 4x^2 + 100 = 0 - 100...
- math help, correction - Anna has 12 bills in her wallet, some $5 and some $10. ...
- Calculus - The cost (in dollars) of producing x units of a certain commodity is ...
- Pre-Algebra - Can I have someone check this please? I wouldn't want to do the ...
- Algebra 2 - Find the values of the 30th and 90th percentiles of the data. Please...
- math - I am doing something wrong when I work this question. Can someone show me...
- statistics - A professional basketball player has embarked on a program to study...
- Algebra2 Help please - Find the values of the 30th and 90th percentiles of the ...
- 6th grade math - Hi.. i'm a little confused on using proprtion equations to ...

More Related Questions