SOLUTION: Given that ab+c=k and ac+k=n,express 'a' in terms of b,c and n only. Hence or otherwise find the value of 'a' if b=0.75, c=0.25 and n=6.5

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Given that ab+c=k and ac+k=n,express 'a' in terms of b,c and n only. Hence or otherwise find the value of 'a' if b=0.75, c=0.25 and n=6.5      Log On


   

Question 859468: Given that ab+c=k and ac+k=n,express 'a' in terms of b,c and n only. Hence or otherwise find the value of 'a' if b=0.75, c=0.25 and n=6.5
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
You want to eliminate k. Solve one equation for k, and substitute this into the other equation.

k=n-ac from second equation.
-
ab%2Bc=k
ab%2Bc=n-ac
ab%2Bac%2Bc=n
ab%2Bac=n-c
a%28b%2Bc%29=n-c
highlight%28a=%28n-c%29%2F%28b%2Bc%29%29

Evaluate then, this expression according to the variable assignments:
a=%286.5-0.25%29%2F%280.75%2B0.25%29