Me, i'm lost.
astronomers classify stars according to their brightness by assigning them a stellar “magnitude.” the higher the magnitude the dimmer the star. the dimmest stars visible to the naked eye have stellar magnitudes of 6. the table below shows the relative brightness of different stellar magnitudes.

a. y = 250 (0.4)^x

b. 0.066

Step-by-step explanation:

The equation can be modeled as a geometric sequence, where the first term is 100 and the common ratio is 0.4.

y = 100 (0.4)^(x − 1)

This can also be simplified to:

y = 250 (0.4)^x

When x = 9:

y = 250 (0.4)^9

y = 0.066

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540

total amount to be paid = $19.5

step-by-step explanation:

given ,

original price = $25.99

discount = 25%

discount amount = 25% of original price

discount amount = 25/100   * 25.99

discount amount = $6.49

hence , the total amount to be paid = original price - discount amount

                                                            = $25.99 - $6.49

                                                            =$19.5

total amount to be paid = $19.5