Show that 155 can be expressed as the sum of a power of 2 and a cube number
Answers
Answered by
29
Answer : ![\bold{2^7 + 3^3 \: = \: 155} \bold{2^7 + 3^3 \: = \: 155}](https://tex.z-dn.net/?f=+%5Cbold%7B2%5E7+%2B+3%5E3+%5C%3A+%3D+%5C%3A+155%7D+)
Explanation -
Given that 155 can be expressed as the sum of a power of 2 and a cube Numbers
Let the power of 2 is 7.
According to the given question -
![{2}^{7} + {x}^{3} = 155 {2}^{7} + {x}^{3} = 155](https://tex.z-dn.net/?f=+%7B2%7D%5E%7B7%7D+%2B+%7Bx%7D%5E%7B3%7D+%3D+155)
Solve x -
![{2}^{7} + {x}^{3} = 155 {2}^{7} + {x}^{3} = 155](https://tex.z-dn.net/?f=+%7B2%7D%5E%7B7%7D+%2B+%7Bx%7D%5E%7B3%7D+%3D+155)
![128 + {x}^{3} = 155 128 + {x}^{3} = 155](https://tex.z-dn.net/?f=128+%2B+%7Bx%7D%5E%7B3%7D+%3D+155)
![{x}^{3} = 155 - 128 {x}^{3} = 155 - 128](https://tex.z-dn.net/?f=+%7Bx%7D%5E%7B3%7D+%3D+155+-+128)
![{x}^{3} = 27 {x}^{3} = 27](https://tex.z-dn.net/?f=+%7Bx%7D%5E%7B3%7D+%3D+27)
![x = {3}^{3} x = {3}^{3}](https://tex.z-dn.net/?f=x+%3D+%7B3%7D%5E%7B3%7D+)
So, 128 + 27 = 155
Hence :
Explanation -
Given that 155 can be expressed as the sum of a power of 2 and a cube Numbers
Let the power of 2 is 7.
According to the given question -
Solve x -
So, 128 + 27 = 155
Hence :
Answered by
9
Answer:
2⁷ + 3³
Step-by-step explanation:
We know that one of the number is 2ⁿ
Therefore, we try:
155 - 2¹ = 153 (But ∛153 ≠ integer)
155 - 2² = 151 (But ∛151 ≠ integer)
155 - 2³ = 147 (But ∛147 ≠ integer)
155 - 2⁴ = 139 (But ∛139 ≠ integer)
155 - 2⁵ = 123 (But ∛123 ≠ integer)
155 - 2⁶ = 91 (But ∛92 ≠ integer)
155 - 2⁷ = 27(∛27 ≠ 3)
So the answer is 2⁷ + 3³
Answer: 2⁷ + 3³
Similar questions