Dan started with 69 cards
Step-by-step explanation:
Let x be the initial number of cards
Then
According to "Dan bought 7 new baseball trading cards to add to his collection"

The next day his dog ate half of his collection.

There are now only 38 cards left.

Multiplying both sides by 2

Subtracting 7 from both sides

Hence,
Dan started with 69 cards
Keywords: Linear equation, word problems
Learn more about linear equations at:
#LearnwithBrainly
Answer:
<em>8 C sometimes</em>
<em>9 64x^8 y^11</em>
<em>10 c 1.28r^2/ t^9</em>
Step-by-step explanation:
<u>Algebraic Operations
</u>
Some basic rules must be fresh in our minds when trying to simplify complex algebraic expressions. For example, the power rule respect to the product or quotient:



Let's face the questions at hand
8. A number is raised to a negative exponent is negative?
Following the expressions recalled above, let's pick the expression

This is a negative power resulting in a positive number
Now we pick

This time, the negative power leads to a negative result, so it doesn't matter the sign of exponent to determine the sign of the result
<em>Answer: C sometimes
</em>
9 simplify(4xy^2)^3(xy)^5



10 simplify(2t^-3)^3(0.4r)^2




Then make up a word problem that you can use decimals in.
Answer:
I would set this up as:
let: lesser number = x
greater number = 2x + 5
Restating the word problem:
lesser number + greater number = 38
x + 2x + 5 = 38
Solving: 3x + 5 = 38
- 5 -5
---------------
3x = 33
--- ---
3 3
x = 11
Substitution for the greater number:
2(11) + 5
22 + 5
27