Given that y is directly proportional tox, and when y = 8 when x= 10.
(a) Write down the equation of y in terms of x.
(b) Find the value of y when x = 25.
8
(c) Find the value of x when y==
25

see explanation

Step-by-step explanation:

(a)

Given that y is directly proportional to x then the equation relating them is

y = kx ← k is the constant of proportion

To find k use the condition y = 8 when x = 10. then

8 = 10k ( divide both sides by 10 )

0.8 = k

y = 0.8k ← equation of proportion

(b)

when x = 25, then

y = 0.8 × 25 = 20

(c)

when y = 25, then

25 = 0.8x ( divide both sides by 0.8 )

x = 31.25

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

i did it myself and i got 4.2 (b) hope its right

step-by-step explanation: