Answer:
The price of the stereo is $300
Step-by-step explanation:
we know that
The sales tax in decimal form multiplied by the price of the stereo must be equal to $21
Let
x -----> the price of the stereo
[tex]Sales\ tax=7\%=7/100=0.07[/tex] -----> decimal form
so
The linear equation that represent this situation is
[tex]0.07x=21[/tex]
Solve for x
Divide by 0.07 both sides
[tex]0.07x=21[/tex]
[tex]x=\$300[/tex]