Question

calculați a-b,unde a= 300+301+302+...+350 și b=305+306+...+350

Answer 1

a- b = (300+301+..+350)-(305+306+...+350)
=300+301+302+303+304
=1510

Answer 2

   
[tex]a= 300+301+302++303+304+305+306+\cdots+350\\ b=305+306+...+350\\\ a-b = 300+301+302+303+304+305+306+\cdots+350 -\\ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-(305+306+...+350)\\\\ a-b = 300+301+302+303+304 = 5 \times 300 +(0+1+2+3+4) =\\\\ =1500 + 10 = 1510 \\\\ \boxed{\bf a-b = 1510}[/tex]