Find the sales tax rate of 278.75 if the tax rate is 6%

The sales tax price is $16.72 
The total amount spent is $295.47 

Hope this helped :)

15.
4(x-2) = 2(x-4)+2x
i used the distributive property on the parantheses to then get...
4x-8 = 2x-8+2x
I combined the like terms to then get...
4x-8 = 4x-8
+8 +8
4x = 4x
which simplifies to
x=x
so the answer to question 15 is x=x

17.
-4(p+1) = -2(8-2p)
I used the distributive property on the parantheses
-4p-4 = -16+4p
+4 +4
-4p = -12+4p
-4p -4p
-8p = -12
÷-8 ÷-8
p = 1.5

so the answer to question 17 is p = 1.5

hope this helps