Posted by **Teri** on Wednesday, September 13, 2006 at 8:40pm.

could someone please help me with these problems i am having trouble.

If y=36 when x =6 find x when y = 42

If y=-18 when x=6 find x when y=6

If y =12 when x= 15 find x when y =21

If y=-6.6 when x=9.9 find y when x =6.6

If y=6 when x=(2/3)find x when y=12

those are the problems you dont have to do all just at least show me step by step how you arrived at the answer thank you so much for helping

take the first one:

y1/y2 = x1/x2

y1=36 x1 is 6

y2=42 x2 is ?

then

36/42=6/x solve for x

and

x=42*6/36 =7

check my thinking.

hyng bbncnnh gbgbn

These are proportion problems

(1) 6:36=x:42 Which is the same as (6*42)/36=x

(2)6:18=x:6 Which is the same as (6*6)/18=x

(3) 15:12=x:21 I think you can do them now

(4)9.9:-6.6=6.6:y Watch where the y is located here.

(5)(2/3):6=x:12 Be sure to handle the fraction correctly.

In general, a proportion is two ratios a:b=c:d

a and d are called the extremes and b and c the means.

The fundamental relation is a*d=b*c The product of the extremes = the product of the means.

You can also think of it in terms of fractions a/b = c/d. in terms of fractions both ratios are different names for the same fraction. One is a multiple of the other. In the first one we have

6:36 or 6/36=1/6

We want to find x such that x/42 = 1/6 so x=42*(1/6)

You can verify that 1/6 = 6/36 = 7/42.

The fraction 1/6 would be the fraction in lowest terms in integers. In some places finding that lowest reducible integer fraction is very important. Other times we can't find such an integer ratio, e.g. if the numbers are irrational.

If y =12 when x= 15 find x when y =21

y=kx 21

## Answer this Question

## Related Questions

- Algebra 2 Honors - Hey, we recently started a topic in class that I don't ...
- Algebra 2 - I am trying to figure out if these problems are Direct Variation, ...
- Math - I am doing Direct Variation in math. I dont understand how to do it. It ...
- Math: Direct Variation - what are the formulas that illustrates direct blinear ...
- PreCalculus - I'm having trouble with these problems.. Could someone please ...
- Algebra 2 - Is the relationship between the variables in the table a direct ...
- Stuck on Algebra 1 - This is kind of like the first question I asked, and I'm ...
- Math- steve or ms. sue - does the data in the table represent a direct variation...
- Math - I need the answers and the work shown steb by step today pls^^ For each ...
- algebra - Tell whether equation represents direct variation. If so, identify the...

More Related Questions