Question

[Thanh tâm]

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Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(=57^2+2\cdot57\cdot43+43^2\)

\(=\left(57+43\right)^2=100^2=10000\)

b: \(=\left(50-49\right)\left(50+49\right)+\left(48-47\right)\left(48+47\right)+...+\left(2-1\right)\left(2+1\right)\)

\(=50+49+48+...+2+1\)

Số số hạng là (50-1):1+1=50(số)

Tổng là: \(\dfrac{51\cdot50}{2}=51\cdot25=1225\)

c: \(=\left(2016-16\right)\left(2016+16\right)=2032\cdot2000=4064000\)

d: \(=\left(950-850\right)\left(950+850\right)=100\cdot1800=180000\)