total tax : $12.24
total cost of the drone after tax :$154.23
Step-by-step explanation
Step 1
a) let

b) now, to find the value of the tax, use the formula

so,replacing

so, total tax : $12.24
Step 2
b)total cost after tax
to find the total cost just add the total tax to the cost before taxes, so

replace

therefore
total cost of the drone after tax :$154.23
I hope this helps you