Question

Bài 1: Tính giá trị biểu thức

1) \(\frac{84^2-16^2}{37^2-63^2}\)

2) \(199^2\)

3) \(31^2\)

4) 45.55

5) 78.82

6) \(M=3\frac{1}{117}.\frac{1}{119}-\frac{4}{117}.5\frac{118}{119}-\frac{5}{117.119}+\frac{8}{39}\)

7) \(A=4\left(3^2+1\right).\left(3^4+1\right)...\left(3^{33}+1\right)\)

Answer 1

1/\(\frac{84^2-16^2}{37^2-63^2}=\frac{\left(84-16\right)\left(84+16\right)}{\left(37-63\right)\left(37+63\right)}=\frac{68.100}{-26.100}=\frac{-68}{26}=\frac{-34}{13}\)

2/ \(199^2=\left(200-1\right)^2=40000-400+1=39601\)

3/ \(31^2=\left(30+1\right)^2=900+60+1=961\)

4/ \(45.55=\left(50-5\right)\left(50+5\right)=50^2-25=2500-25=2475\)

5/ \(78.82=\left(80-2\right)\left(80+2\right)=80^2-4=6400-4=6396\)