Neil needs to mail a cd to friend. he uses 40-cent stamps and 7-cent stamps to pay $2.56 in postage. how many of each stamp did he use

He used five 40-cent stamps and eight 7-cent stamps.

Step-by-step explanation:

Let x represent the number of 40-cent stamps that he used.

Let y represent the number of 7-cent stamps that he used.

41 cents = 40/100 = $0.40

7 cents = 7/100 = $0.07

He uses 40-cent stamps and 7-cent stamps to pay $2.56 in postage. It means that

0.4x + 0.07y = 2.56

Multiplying through by 100, it becomes

40x + 7y = 256

7y = 256 -40x

We would test for corresponding values of x and y that satisfies the equation and they must be whole numbers.

If x = 4,

7y = 256 - 40 × 4 = 96

y = 96/7 = 13.71

If x = 5,

7y = 256 - 40 × 5 = 56

y = 56/7 = 8

step-by-step explanation:

i found the koficent of the linear function and i foun c acordind to the strict formula y=kx+c and then i took 2 as an x and replacet it on the formula i found and then foun the y