Tuesday

September 30, 2014

September 30, 2014

Posted by **JERSEYGIRL** on Sunday, December 4, 2011 at 8:49pm.

x x - 20 This is a three part question>> first find the lcd method of solving this equations, and the second ones about cross-multiplying method to solve this equations ,The next question asked would the cross- multiplying method work for all rational equations?? Explain.

- Algebra -
**Reiny**, Sunday, December 4, 2011 at 9:02pmI am guessing you are trying to type the equation

40/x = 15/(x-20)

The LCD is x(x-20_

so

40/x (x(x-20)) = 15/(x-20) (x(x-20))

40(x-20) = 15x

40x - 800 = 15x

25x = 800

x = 32

cross-multplying gets you directly to

40(x-20) = 15x

etc

Cross-multiplying only works if your equation contains a single term on the left and a single term on the right,

that is,

you have to add/subract the terms first if you have more than one.

In that case I simply multiply each term by the LCD, to get rid of my fractions.

- Algebra -
**JERSEYGIRL**, Sunday, December 4, 2011 at 9:42pm(1)40 =15 (2) x - 20 (2 DIFFERENT EQUATIONS)????? help please!!!!

**Answer this Question**

**Related Questions**

Algebra - Solving system of linear equations by using the apropiate method name ...

Algebra - I am trying to solve the sytems of equations using the elimination ...

Psy - Complate the following chart. The first column shows the name of a ...

algebra - Explain the difference between solving a system of equations by the ...

PSY 210 - Complete the following chart. The first column shows the name of a ...

Algebra - When is the substitution method a better method than graphing for ...

Algebra - Is there a difference between solving a system of equations by the ...

Business Algebra - Produce an example of a system of equations to your fellow ...

algebra - How would you explain to a 6th grader the difference between solving a...

ALGEBRA - Find the choice below which gives a first step in solving the given ...