Answer:
$96.74
Explanation:
The original cost of the Amazon echo = $99.99
Then we have a 10% sale which we are going to subtract from the original cost.
= $99.99-(99.99x10%)
= 99.99-9.999
= $89.991
Then a tax of 7.5% was added
= $89.991 + (89.991 x 7.5%)
= 89.991 + 6.749325
= $96.740325
Therefore the cost of the echo including tax is $96.74