Write an algebraic expression to represent the cost of a mp3 download for m dollars with a $2 off coupon

x => hamburgers

y => hot dogs

x + y = 26

3.5x + 2y = 70

-2x - 2y = -52

3.5x + 2y = 70

1.5x = 18

x = 18 / 1.5 = 12

y = 26 - 12 = 14

they sold 12 hamburgers and 14 hot dogs

answer: y = 4*0.5^x

explanation:

first we'll use the point (1,2) to isolate c in terms of 'a'

y = c*a^x

2 = c*a^1 plug in (x,y) = (1,2)

2 = c*a

c = 2/a

the use the last equation mentioned above, along with the second point (2,1) to determine the value of 'a'

y = c*a^x

y = (2/a)*a^x replace c with 2/a

y = 2*a^(-1)*a^x

y = 2a^(-1+x)

1 = 2a^(-1+2) plug in (x,y) = (2,1)

1 = 2a^1

1 = 2a

a = 1/2 = 0.5

this value of 'a' leads to

c = 2/a

c = 2/0.5

c = 4

since a = 0.5 and c = 4, the answer is y = 4*0.5^x

answer:

8

step-by-step explanation:

both numbers are negative so they cancel each other out and the equation becomes 40/5 which is 8

to prove= 5*8=40