Question

You buy 1 balloon and 1 banner for $3. Your friend buys 5 balloons and 2 banners for $9. What is the cost of each balloon? of each banner?

Answer 1

We can start solving the problem using systems of equations. Let x be the cost of each balloon and y be the cost of each banner. We know from the problem that:

1x + 1y = 3 (the cost of 1 balloon and 1 banner is $3)

5x + 2y = 9 (the cost of 5 balloons and 2 banners is $9)

We can use the first equation to solve for one of the variables in terms of the other, and substitute that into the second equation. Then we can solve for the remaining variable.

From equation 1:

y = 3 - x

We can substitute this into equation 2:

5x + 2(3 - x) = 9

Which simplifies to:

5x + 6 - 2x = 9

3x = 3

x = 1

So each balloon costs $1

We can now substitute x=1 in the first equation:

1*1 + 1y = 3

y = 2

So each banner costs $2

Answer 2

Explanation:

Let us assume the cost of

• balloon be x
• banner be y

In first case , cost of 1 1 balloon and 1 banner is $3 . We can set up a equation as ,

1*x + 1*y = 3

x + y = 3 . . . . . (i)

In second case, cost of 5 balloons and 2 banners is $9 . So ,

5*x + 2*y = 9

5x + 2y = 9 . . . . . (ii)

From equation i and ii , we have ,

5(3-y) + 2y = 9

15 - 5y + 2y = 9

15 - 3y = 9

3y = 15 -9

3y = 6

y = 2

And we had ,

x + y = 3

x + 2 = 3

x = 3 - 2

x = 1

Hence,

• cost of balloon= x = $1
• cost of banner= y = $2

and we are done!