Question

Tính giá trị biểu thức :

a) \(5\dfrac{5}{27}+\dfrac{7}{23}+0,5-\dfrac{5}{27}+\dfrac{16}{23}\)

b) \(\dfrac{3}{8}.27\dfrac{1}{5}-51.\dfrac{1}{5}.\dfrac{3}{8}+19\)

Answer 1

Dấu " / " là phân số nhé :

a) 5 5/27 + 7/23 + 0,5 - 5/27 + 16/23

= 140/27 + 7/23 + 1/2 - 5/27 + 16/23

= ( 140/27 - 5/27 ) + ( 7/23 + 16/23 ) + 1/2

= 5 + 1 + 1/2

= 6 + 1/2

= 13/2

b) 3/8 . 27 1/5 - 51 .1/5 . 3/8 + 19

= 3/8 . 136/5 - 51 . 1/5 . 3/8 + 19

= 3/8 . ( 136/5 - 1/5 ) - 51 + 19

= 3/8 . 27 - 51 + 19

= 81/8 - 52 + 19

= -183/8

Answer 2

Sorry nha mik sửa lại con B

b) 3/8 . 27 1/5 - 51 . 1/5 . 3/8 + 19

= 3/8 . 136/5 - 51/5 . 3/8 + 19

= 3/8 . ( 136/5 - 51/5 ) + 19

= 3/8 . 17 + 19

= 51/8 + 19

= 203/8