Answer:
Explanation:
Let x be the number of cards Jason had initially in his collection.
"Jason bought 9 new baseball trading cards to add to his collection"
x
+
9
is the equation because
x
is the initial number of cards he has and he bought another 9
"His dog ate half of his collection"
1
2
(
x
+
9
)
because
x
+
9
is what he had before his dog ate his cards and since his dog ate half, there is a
1
2
added to the equation
"42 cards left"
1
2
(
x
+
9
)
=
42
Since his dog ate half, he is left with half of his initial card collection.
x
+
9
=
42
×
2
x
+
9
=
84
x
=
84
−
9
x
=
75