A diamond today cost ten dollars more than twice what it cost last year. The sum of the cost (last year and this year) is $2500. What is the cost of last year diamond? What are the reasonable domain and range?

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

sup

step-by-step explanation:

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl