Question

Rita goes to the mall. If d is the number of items she bought the expression 13.91d + 21 gives the amount she spent at one store then she spent $28 at another store. find the expression which represents the amount Rita spent at the mall then estimate how much Rita spent if she bought four items.what expression represents the amount in dollars that rita spent at the mall?

Answer 1

Let us assume that Rita only goes to two stores. The total amount that Rita spends at the mall is simply the addition of what she spent in each store independently.

In this case, at store 1 she spent

$13.91\cdot d+21$

At store 2, she spent

$28$

So the expression that represents the total amount she spent at the mall is simply the addition of this two quantities. So we have

$13.91\cdot d+21+28\text{ = 13.91}\cdot d+49$

This expression applies to the case in which she buys d items. We are told that she bought 4. So we replace d=4 to get the amount she spent. IN this case

$13.91\cdot4+49=104.64$

So Rita spent 104.64 at the mall.