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7. Look at the number sentence below.
1+2+3+4 +-----------+ 80 = 3240
71 +72+73+ ---------+ 80 = 755
What is the sum of numbers from 1 to 70?
a)3240-10
b) 3240-80
c) 3240 +755
d) 3240-755

Respuesta :

Medunno13

Answer: 3240-755

Step-by-step explanation:

We know that:

[tex](1+2+\cdots+80)-(71+72+\cdots+80)=1+2+\cdots+70[/tex]

Thus, [tex]1+2+\cdots+70=\boxed{3240-755}[/tex]

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