Answer:
They are all true
Step-by-step explanation:
1. 3² +4² = 5²
3x3 + 4x4 = 5x5
9 + 16 = 25
25 = 25
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2. 6² + 8² = 10²
36 + 64 = 100
100 = 100
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3. 9² + 12² = 15²
81 + 144 = 225
225 = 225
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4. 5² +12² =13²
25 + 144 = 169
169 =169
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Answer:
14 hours
Step-by-step explanation:
Let's call the task 3x
The older bro does twice as younger so it would be 2x long and younger brother work x long
Since the totsl of work is 3x = 21 x woul be 21÷3 = 7
the older brother must work 2 × 7 = 14 hours long
