The tables show the cost of different numbers of t-shirts ordered at two different stores, Store C and Store D: Store C

Number
of T-shirtsCost (in $)
2$12
4$24
8$48

Store D

Number
of T-shirtsCost (in $)
3$21
6$42
9$63

Which of these explains which store has a better buy?
Store C, because the ratio of the number to the cost is 6:1 in Store C and 7:1 in Store D.
Store C, because the ratio of the number to the cost is 1:6 in Store C and 1:7 in Store D.
Store D, because the ratio of the number to the cost is 2:14 in Store C and 3:24 in Store D.
Store D, because the ratio of the number to the cost is 14:2 in Store C and 24:3 in Store D.

45

step-by-step explanation:

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

b. hoped i'm right lol

step-by-step explanation: