Explanation:
Let x = number of free throws Susie made.
Let y = number of 2-point shots Susie made.
Let's make a system to represent this:
x + y = 10
x + 2y = 18 (every y shot makes 2 points, x shot makes 1 point)
By subtracting one equation from the other, we can cancel out the x. This is called "elimination".
x + y = 10
-x + 2y = 18
-y = -8
y = 8
Now, since these equations should be equal, you can plug 8 in for y in any of these equations to get x.
x + 8 = 10
x + 8 = 10
- 8 -8
x = 2
Set of solutions: x = 2; y = 8.
Remember from above, x represents the amount of free throws and y represents the amount of 2-point shots.
Sophie made 2 free throws and 8 two-point shots.