This is a system of equations problem. You can either solve it with elimination or substitution.

Let c = candy bar and b = bubble gum.

Elimination:

c + b = $1.50, and c - b = $1

Add the equations

c + b + c + (- b) = $1.50 + $1

2c = $2.50

**c = $1.25**

$1.25 + b = $1.50

**b = $0.25**

Substitution:

c + b = $1.50, and c - b = $1

c = $1.50 - b, so $1.50 - b - b = $1

$1.50 - 2b = $1

- 2b = - $0.50

**b = $0.25**

Since we don't actually have to solve for the candy bar, we can stop.