Please help me with math

part one:

6 3

22 1

30 0

part two:

0.50*s+4*a=15

Step-by-step explanation:

part one:

firstly:

6 individual songs cost 6*0.50= 3 dollars

she has 15 dollars so after downloading 6 individual songs that cost 3 dollars together

it means that she has only 15-3=12 dollars to download full albums

so 12/4=3 albums

because 4 dollar cost one album and with 12 dollars she can buy just 3 albums

secondary:

she downloaded 1 album

and one album cost 1*4=4 dollars

she has 15 dollars ,after buying 1 album

she has 15-4=11 dollars

so she can download 11/0.50=22 individual songs

so she can download 22 individual songs.

the last one:

she downloaded 30 individual songs

that all together cost 30*0.50=15 dollars

but she has 15 dollars at all so she cant buy any album because she spent all her money in individual songs.

because 15-15=0 money left

part two:equation

0.50*s+4*a=15

step-by-step explanation:

ask goog great chance of finding the solution there

step-by-step explanation: