posted by dan on .
The number of dogs and chickens on a farm add up to 14. The number of legs between them is 36. How many dogs and how many chickens are on the farm if there are at least twice as many chickens as dogs?
D = 14 - C
4D + 2C = 36
Substitute 14-C for D in second equation and solve for C. Insert that value into the first equation and solve for D. Check by inserting both values into the second equation.