Explicație pas cu pas:
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..
a) D15= {1,3,5,15}
X+1€ aparține divizorii lui 15
(x+1))={1,3,5 ,15}=>x€ lui {0,2,4 14}
b) D26={ 1,2,13,26}
2x+1 | 26
(2x+1)={1,2,13,26}=>2x={0,1 ,13,25}. x={0,6}
c) D32={1,2 ,4,8,16,32}
2X+4|32
2x+4={1,2,4,8,16,32}
2×={0,4,12,28}
x={0,2,6,14}
d)D70={1,2,5,7,10,14 35,70}
2x+5={1,2 5,7,10,14 ,35,70}
2x={0,2,5,9,30,65}
x= {0,1,15}
e) D45={1,3,5,9,15,45}
3x-3={1,3 ,5 9,15,45}|-3
3x= {0,2,6,12,43}÷3
x= {0,2,4,14}