Question

Bài 1 : tính hợp lý nếu có thể

a, -1/2 + 2/7 - 5/28

b, 5 3/4 + ( 1/9 - 1 3/4 )

c, -5/7 . 2/11 + -5/7 . 9/11 + 3 5/7

Giúp mình với, làm đầy đủ mình tick please

Answer 1

#)Trả lời :

a)   \(\frac{-1}{2}+\frac{2}{7}-\frac{5}{28}\)

    \(=\frac{-3}{14}-\frac{5}{28}\)

    \(=\frac{-11}{28}\)

b)  \(5\frac{3}{4}+\left(\frac{1}{9}-1\frac{3}{4}\right)\)

   \(=\left(5\frac{3}{4}-1\frac{3}{4}\right)+\frac{1}{9}\)

   \(=4+\frac{1}{9}\)

   \(=4\frac{1}{9}=\frac{37}{9}\)

c)  \(\frac{-5}{7}x\frac{2}{11}+\frac{-5}{7}x\frac{9}{11}+3\frac{5}{7}\)

   \(=\frac{-5}{7}x\left(\frac{2}{11}+\frac{9}{11}\right)+3\frac{5}{7}\)

   \(=\frac{-5}{7}x1+3\frac{5}{7}\)

   \(=\frac{-5}{7}+3\frac{5}{7}\)

   \(=\frac{-5}{7}+\frac{26}{7}\)

   \(=\frac{21}{7}=3\)

            #~Will~be~Pens~#