[Rookie]

ok so we did this lab in which we were given an unknown concentration of glocuse and we had to find this concentration by only knowing the absorbance of the glucose (which we did through experiment) along with the absorbances and concentration of 4 calibration standards (which we also figured out through experiment). After plotting absorbance vs. concentration, the calibration curve for these 4 standards is:
                     0.289 = 0.0018x + 0.0211  
Now, my question is this: To find the concnetration of my unknown, do I simply take the absorbance of my uknown and divide it by the slope? (0.0018) Or do i replace "y" in the equation with my absorbance of my unknown and solve for x (x being my concentration)    thank you!

[shifthappens]

I'm a little confused. A proper absorbance calibration using the beer-lambert law would give you a linear equation (y=mx+b) where y is absorbance and x is the concentration. What you posted is just a line where x equals something.

I'm going to assume you just made a mistake and the calibration line is in fact:
y = 0.0018x + 0.0211
not

0.289 = 0.0018x + 0.0211

From here on, its just basic 6th grade algebra. You should have measured the absorbance of your unknown in lab. Plug it into your calibration equation and it will give you a concentration.

[Rookie]

yes, you are right I did make a mistake..my line came out to be y=0.0018x + 0.0211, but when I posted, I already plugged in the absorbance of my unknown as "y" ... and yes I just plugged in and it gave me my concentration.