Question 48130
Let P = number of peaches and A = number of apples. From the problem description, you can write:

A = P+12 and, when Mary divides each fruit in half, she will double the number of pieces of fruit, right?:
2A+2P = 32 Simplift this by dividing both sides by 2.
A+P = 16 Now substitute A = P+12 into this equation to find P, the number of peaches.

(P+12) + P = 16 Simplify this.
2P + 12 = 16 Subtract 12 from both sides.
2P = 4 Divide both sides by 2.
P = 2

Mary has 2 peaches.