Question

Tính nhẩm bằng cách áp dụng tính chất a(b-c)=ab+ac

8.19;65.98

Answer 1

8.19 = 8.(20-1) = 8.20-8 = 160-8 = 152

65.98 = 65.(100 - 2) = 65.100 - 65.2 = 6500-130 = 6370

Answer 2

\(\text{8.19}\)

\(=8.\left(20-1\right)\)

\(=8.20-8.1\)

\(=160-8\)

\(=152\)

\(65.98\)

\(=65.\left(100-2\right)\)

\(=65.100-65.2\)

\(=6500-130\)

\(=6370\)