已知1^2+2^2+3^2+4^2+…+n^2=1/6n(n+1)(2n+1) 则2^2+4^2+6^2+100^2=
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![已知1^2+2^2+3^2+4^2+…+n^2=1/6n(n+1)(2n+1) 则2^2+4^2+6^2+100^2=](/uploads/image/z/2688995-11-5.jpg?t=%E5%B7%B2%E7%9F%A51%5E2%2B2%5E2%2B3%5E2%2B4%5E2%2B%E2%80%A6%2Bn%5E2%3D1%2F6n%28n%2B1%29%282n%2B1%29+%E5%88%992%5E2%2B4%5E2%2B6%5E2%2B100%5E2%3D)
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已知1^2+2^2+3^2+4^2+…+n^2=1/6n(n+1)(2n+1) 则2^2+4^2+6^2+100^2=
已知1^2+2^2+3^2+4^2+…+n^2=1/6n(n+1)(2n+1) 则2^2+4^2+6^2+100^2=
已知1^2+2^2+3^2+4^2+…+n^2=1/6n(n+1)(2n+1) 则2^2+4^2+6^2+100^2=
2^2+4^2+6^2+100^2= (1*2)^2+(2*2)^2+…+(50*2)^2=4*(1^2+2^2+…+50^2)=4*(1/6)*50*51*101
=171700
原式=(1*2)^2+(2*2)^2+(3*2)^2+(4*2)^2++…+(2*50)^2(提公因式+2^2)
=2^2*(1^2+2^2+3^2+4^2+…+50^2)
=2^2*[1/6*50*(50+1)(2*50+1)]=2^2*42925=171700