Question

[Trần Mai Trang]

Tính nhanh

a) 45kg * 2 + 45kg + 45kg + 45kg * 2 + 45kg *3

b) 16* 48 + 8 * 48 + 16 * 48

Answer 1

[Mỹ Anh]

a ) 45 kg x 2 + 45 kg + 45 kg x 2 + 45 kg x 2 + 45 kg x 3

= 45 kg x 2 + 45 kg x 1 + 45 kg x 2 + 45 kg x 2 + 45 kg x 3

= 45 kg x ( 2 + 1 + 2 + 2 + 3 )

= 45 kg x 10

= 450 kg

b ) 16 x 48 + 8 x 48 + 16 x 48

= ( 16 + 8 + 16 ) x 48

= 40 x 48

= 1920