Which of the following expressions is not a perfect cube? *
1 point
5 x 10 x 32X 3
125 x 8 x 125
15 x 8 x 25 x 9
49 x 21 x 27 x 8
Answers
Step-by-step explanation:
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1.
=> 5 * 10 * 32 * 3 = 5 * 5 * 2 * 2^5 * 3 = 5^2 * 2^6 * 3
THIS IS NOT A PERFECT CUBE.
2.
=> 125 * 8 * 125 = 5^3 * 2^3 * 5^3 = 25^3 * 2^3.
THIS IS A PERFECT CUBE.
3.
=> 15 * 8 * 25 * 9 = 3 * 5 * 2^3 * 5^2 * 3^2 = 2^3 * 3^3 * 5^3.
THIS IS A PERFECT CUBE.
4.
=> 49 * 21 * 27 * 8 = 7^2 * 3 * 7 * 3^3 * 2^3 = 7^3 * 3^4 * 2^3
THIS IS NOT A PERFECT CUBE.
HOPE IT HELPS!!!!
PLS THNK MY ANSWERS!!!!
1. Resolve (5×10×32×3 ) into prime factors ,we get
5×10×32×3
= 5 × 2 × 5 × 2×2×2×2×2×3
= 2×2×2× 2×2×2 ×3 × 5×5
The prime factors 3 and 5 doesn't appear in a group of three.
So, 5×10×32×3 is not a perfect cube.
2. Resolve (125 × 8 × 125 ) into prime factors ,we get
125 × 8 × 125
= 5 × 5 × 5 × 2 × 2 × 2 × 5 × 5 × 5
Each factor appear three times .
Therefore.,
So, (125 × 8 × 125 ) is a perfect cube .
3. Resolve (15 × 8 × 25 × 9 ) into prime factors ,we get
15 × 8 × 25 × 9
= 3 × 5 × 2 × 2 × 2 × 5 × 5 × 3 × 3
= 2 × 2 × 2 × 3 × 3 × 3 × 5 × 5 × 5
Each factor appear three times .
Therefore.,
So, (15 × 8 × 25 × 9 ) is a perfect cube .
4. Resolve (49 × 21 × 27 × 8 ) into prime factors ,we get
49 × 21 × 27 × 8
= 7 × 7 × 3 × 7 × 3× 3 × 3 × 2 × 2 × 2
= 2 × 2 × 2 × 3 × 3 × 3 × 3 × 7 × 7 × 7
The prime factor 3 doesn't appear in a group of three .
Therefore.,
So, (49 × 21 × 27 × 8 ) is not a perfect cube .
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