Quandaries and Queries
  

 

Hi
I was hoping that you could help me with this problem.  I believe that this is a high school level problem but as an adult who has forgotten the "rules", I am stuck.
 
the equation is this:   x=t2/(t1-t2)
 
we know that x=5.73
                     t1=303
 
we must solve for t2
 
Thank you
Anthony
 

 

Hi Anthony,

An equation is like a balance. You can can change one side by adding, subtracting, multiplying or dividing a quantity as long as you perform the identical operation on the other side also. The goal is to obtain an equivalent equation of the form

t2 = some quantity.

In your equation

x = t2/(t1-t2)

I would first multiply both sides by t1-t2 to get

x (t1 - t2) = t2/(t1-t2) (t1-t2)

so

x (t1 - t2) = t2

Expanding the left side gives

x t1 - x t2 = t2

You want one side of the equation to have only t2 so add x t2 to both sides to get

x t1 - x t2 + x t2 = t2 + x t2

which simplifies to

x t1 = (1 + x) t2

Now divide both sides by (1 + x) to obtain

 (x t1)/(1+x) = t2

You have x = 5.73 and t1 = 303 so

t2 = 5.73 303/5.73 + 1 = 1736.19/6.73 = 257.98

Penny

  
 

Go to Math Central