This is a systems of equation problem.
First, set up the equation.
814=w+d w=d-36
Second, insert w= in for w in the equation.
814=d-36+d
Third, combine like terms.
814=2d-36
Fourth, solve the equation by adding 36 and dividing by 2 to both sides.
814=2d-36
+36 +36
___________
850=2d
----- ----
2 2
__________
425=d
So the dryer (d) costs $425.