A stereo system cost $400 with a 20% markup on cost what is the selling price

The mark up is $80 but the over all price is $480

Step-by-step explanation:

$400*20% is 80

But it is a mark up so you add $80 to $400. To get $480.

let x be the money she spent so that she can earn the free t-shirt.

since, she already spent $112.49

⇒

also, as per the statement: jennifer must spend $250 or more in order to qualify for a free t-shirt at the store.

then,

we have an inequality i.,e

subtract 112.49 from both sides we get;

therefore, $137. 51 more money does jennifer need to spend so that she can earn the free t-shirt

the answer would be c:   ax + b = ax + c

step-by-step explanation: