Question

Tính hợp lý:

a)93.85+17.45-170

b)\(\left(\frac{-13}{31}:\frac{5}{17}+\frac{-18}{31}:\frac{5}{17}\right).\frac{25}{34}\)

Answer 1

a) 93. 85+ 17. 45-170 = 93. 17. 5+ 17.9.5-17.5.2= 17.5.( 93+ 9-2)= 85. 100 = 8500

b) \(\left(\frac{-13}{31}:\frac{5}{17}+\frac{-18}{31}:\frac{5}{17}\right).\frac{25}{34}\)

\(=\left(\frac{-13}{31}.\frac{17}{5}+\frac{-18}{31}.\frac{17}{5}\right).\frac{25}{34}\)

\(=\left(\frac{-13}{31}+\frac{-18}{31}\right).\frac{17}{5}.\frac{25}{34}\)

\(=\left(-1\right).\frac{5}{2}\)

\(=\frac{-5}{2}\)

CHÚC BN HỌC TỐT!!
 

Answer 2

a, 98.85 + 17.45 - 170 = 116.3 - 170 = -53.7

b, (-13/31 : 5/17 + -18/31 : 5/17) x 25/34 = 17/5 x ( -13/31 + -18/31) x 25/34

=17/5 x -1 x 25/34 = -5/2 = -2.5