rational models and independent variables

Question

(30*3.1x)/3.1+x=7
I can not figure the out. Please help/

Answer 1

You did not state the problem clearly, Shawna, which is probably why no one has answered it.  As written, it could be either of the following:

 

(30*3.1x)/(3.1+x) = 7

or 

(30*3.1x/3.1) + x = 7

 

 

For (30*3.1x)/(3.1+x) = 7:

 

93x = (3.1+x)*7

93x = 21.7 + 7x

86x = 21.7

x = 21.7/86 = 217/860 ≅ 0.2523

 

For (30*3.1x/3.1) + x = 7:

 

30x + x = 7

31x = 7

x = 7/31 ≅ 0.2258