I need help with this any one please help me

b. y = 1000x

Constant of proportionality = 1,000

Step-by-step explanation:

The equation that represents a proportional relationship between variable x and y usually takes the following form, y = kx.

Where,

k = constant of proportionality.

From the three given equations, the only equation that takes the form is b. y = 1000x.

The constant of proportionality (k) of the equation = 1,000.

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