Hello, lizard4!

This is a very basic problem with a system of equations.

Assuming you're new at this, I'll baby-step through it.

Sally bought three chocolate bars and a pack of gum and paid $1.75.

Jake bought two chocolate bars and four packs of gum and paid $2.00.

Find the cost of a chocolate bar and the cost of a pack of gum

Let = cost of a chocolate bar.

Let = cost of a pack of bum.

Sally bought 3 chocolate bars at cents each.

. . They cost her: . cents.

She bought 1 pack of gum at cents each.

. . This cost her: . cents.

So she spent: .3C + G[/tex] cents.

. . But we are told that she spent 175 cents.

There is one equation: . .[1]

Jake bought two chocolate bars at cents each.

. . This cost him: .[ cents.

He bought 4 packs of gum at cents each.

. . This cost him: . cents.

So he spent: . cents.

. . But we are told that he spent 200 cents.

There is another equation: . .[2]

Solve the system of equations: .

Multiply [1] by -4: .

. . . . . . .Add [2]: . .

And we get: .

Substitute into [1]: .

Therefore: a chocolate bar costs 50¢ and a pack of gum costs 25¢.