Question

Bài 1 Tính nhanh 

a 103^2

b 52×48

c 75^2-50.75+25^2

Answer 1

a) \(103^2=\left(100+3\right)^2=10000+600+9=10609\)

b) \(52\cdot48=\left(50-2\right)\left(50+2\right)=2500-4=2496\)

c) \(75^2-50\cdot75+25^2=\left(75-25\right)^2=50^2=2500\)

Answer 2

\(103^2=\left(100+3\right)^2=100^2+2.3.100+3^2=10000+600+9=10609\)

\(52.48=\left(50+2\right)\left(50-2\right)=50^2-2^2=2500-4=2496\)

\(75^2-50.75+25^2=75^2-25.75-25.75+25^2=75\left(75-25\right)-25\left(75-25\right)=\left(75-25\right)=50^2=2500\)