Janet, Rosi, and Tanya buy postcards from their favorite souvenir shop Janet buys 3 postcards for $1.05 Rosie by five postcards for $1.75 Tanya Buys eight postcards for $3.80 are the cost why in dollars and the numbers of postcards extra personal explain your answer right in equation to represent the relationship if possible

Total Amount spent on all the cards = $ 42.3

No of cards  = 16 .

Step-by-step explanation:

The cost is calculated by multiplying the number of items with their costs. As we have different costs for each card we will add the costs of different cards to get the total costs.

Janet buys 3 postcards for $1.05.

Janet spends 3* $1.05= $ 3.15

Rosie buys five postcards for $1.75

Rosie spends 5 * $ 1.75= $ 8.75

Tanya buys eight postcards for $3.80

Tanya spends 8 * $3.80 = $ 30.4

Total Amount spent on all the cards = $ 3.15+$ 8.75+$ 30.4= $ 42.3

No of cards = 3 + 5+ 8= 16 cards were bought .

answer is the third choice:

3x^5+4x^4+x^3+2x^2-10x-7=0

step-by-step explanation: