Question

[đào phương trang]

tính bàng cách thuận tiện nhất :

a) 27,42 + 51,24 + 22,58 + 48,76

b) 28,67 x 99 + 28,67

Answer 1

[Admin (a@olm.vn)]

a, 27,42 + 51,24 + 22,58 + 48,76

= ( 27,42 + 22,58 ) + ( 51,24 + 48,76 )

= 50 + 100

= 150

b, 28,67 x 99 + 28,67

= 28,67 x ( 99 + 1 )

= 28,67 x 100

= 2867

Answer 2

[ღღ_๖ۣ nhók_lùn ❣_ღღ]

a)   \(\text{27,42 + 51,24 + 22,58 + 48,76}\)

    \(=\left(27,42+22,58\right)+\left(51,24+48,76\right)\)

    \(=50+100\)

    \(=150\)

b)  \(\text{28,67 x 99 + 28,67}\)

    \(=28,67\cdot99+28,67\cdot1\)

    \(=28,67\cdot\left(99+1\right)\)

    \(=28,67\cdot100\)

     \(=2867\)