Given a cost minimizing problem
Min b1x1 + b2x2 .............(1)
x1,x2

Y = f ( x1x2 ) ................(2)

1. Show and explain that the firm will always make a cost minimization.

2. Prove that the rate of technical Substitution must equal the factor price.

first, find X, then when you finish,

find b,

after which you look for the value of y...

if at this point, you're not satisfied, then you can continue to look for the next alphabet, until you exhaust them...