Question 731906
first refrigerator cost
C(x1)=700+85x
C(10)= 700+850
C(10)= 1550

refrigerator II

C(x2) = 1000+25x
C10) =1000+250
C(10)=1250

Now you know it.

same cost
700+85x=1000+25x
60x=300
x= 5 years