Let’s solve each of the first 5 problems step by step using
properties of exponents.
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Problem 1: Simplify
Expression: \( 5x^9 \cdot -6x^2 \)
✔ Step 1: Multiply the coefficients (numbers):
\( 5 \cdot (-6) = -30 \)
✔ Step 2: Multiply the variables with exponents — when multiplying like bases,
add the exponents:
\( x^9 \cdot x^2 = x^{9+2} = x^{11} \)
✔ Final Answer: \( -30x^{11} \)
✔️
Correct Choice: C
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Problem 2: Simplify
Expression: \( (5x^{11})^2 \)
✔ Use the power of a product rule: \( (ab)^n = a^n b^n \)
So, \( (5x^{11})^2 = 5^2 \cdot (x^{11})^2 \)
✔ Calculate each part:
- \( 5^2 = 25 \)
- \( (x^{11})^2 = x^{11 \cdot 2} = x^{22} \) (power of a power: multiply exponents)
✔ Final Answer: \( 25x^{22} \)
✔️
Correct Choice: C
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Problem 3: Simplify
Expression: \( (x^8)(x^{-5}) \)
✔ When multiplying like bases,
add the exponents:
\( x^8 \cdot x^{-5} = x^{8 + (-5)} = x^{3} \)
✔ Final Answer: \( x^3 \)
✔️
Correct Choice: D
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Problem 4: Simplify
Expression: \( (k^2)^5 \)
✔ Use the
power of a power rule: \( (a^m)^n = a^{m \cdot n} \)
So, \( (k^2)^5 = k^{2 \cdot 5} = k^{10} \)
✔ Final Answer: \( k^{10} \)
✔️
Correct Choice: D
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✔ Final Answers:
1.
C – \( -30x^{11} \)
2.
C – \( 25x^{22} \)
3.
D – \( x^3 \)
4.
D – \( k^{10} \)
Let me know if you’d like help with questions 5–15 too!
Parent Tip: Review the logic above to help your child master the concept of integer exponents worksheet.