Question

5. SHOPPING Two stores are having a sale on T-shirts
that normally sell for $20. Store S is advertising an s
percent discount, and Store T is advertising a t dollar
discount. Rose spends $63 for three T-shirts from
Store S and one from Store T. Manny spends $140 on
five T-shirts from Store S and four from Store T. Find
the discount at each store.

Answer 1

Answer:

x=20% discount

y=$5 discount

Step-by-step explanation:

let

x= % of discount

y= amount of discount

Price of t shirt in store S=20 - 20x

Price of t shirt in store T= 20 -y

Rose spends $63 for three T-shirts from store S and one from Store T

Store S=20-20x

Store T=20-y

3 shirts from store S=3(20-20x)

1 from Store T=20-y

3(20-20x) + (20-y)=63

60 - 60x + 20-y=63

-60x - y= -17 (1)

Manny spends $140 on five T-shirts from store S and four from Store T

5(20-20x)+4(20-y)=140

100-100x+80-4y=140

-100x - 4y= -40 (2)

Solve eq 1 and 2

-60x - y= -17

-100x - 4y= -40

Multiply (1) by -4

-4(-60x-y)= -17*-4

240x+4y=68 (3)

-100x-4y=-40 (2)

Subtract (2) from (3)

140x=28

x=28/140

x= 0.2

substitute the value of x in (1)

-60x - y= -17

-60(0.2)-y=-17

-12-y=-17

-y=-17+12

-y=-5

Divide both sides by -1

-y/-1=-5/-1

y=5

Therefore,

x=0.2=20% discount

y=$5