Answer:
The cost of the diamond last year is x = $ 830
Step-by-step explanation:
Let the cost of diamond last year = x
the cost of diamond present year = y
Given that diamond today cost ten dollars more than twice what it cost last year.
⇒ y = 2 x + 10 ------ (1)
The sum of the cost (last year and this year) is = $ 2500
⇒ x + y = $ 2500 -------- (2)
Put the value of y in equation (2) from equation (1), we get
⇒ 2 x + 10 + x = $ 2500
⇒ 3 x = 2490
⇒ x = $ 830
& y = 2500 - 830
⇒ y = $ 1670
Therefore the cost of the diamond last year is x = $ 830
