Answer:
The cost of the dryer is $375.
Explanation:
We can call the washer "w", and the dryer "d".
w+d=815
w=d+65
Now we solve. We can substitute d+65 in for w.
(d+65)+d=815
2d+65=815
2d=750
d=375
w=d+65
Substitute 375 in for d.
w=375+65
w=440
We can check our work. 375+440=815.
Therefore, the dryer cost $375 (and the washer cost $440, but you don't need to know that for this question.)
Hope this helps! If you have any questions, I'll be happy to answer them :)