Question

a. \(A=0.1+0.2+.......+0.19\)

b. \(B=\left(2017\cdot2016+2014\cdot2015\right)\cdot\left(1+\frac{1}{2}:1\frac{1}{2}+1\frac{1}{3}\right)\)

Answer 1

a. ta có (0.1+0.19)+(0.2+0.18)......+0.10 
A=0.20+0.20++0.20+0.20+0.20+0.20+0.20+0.20+0.20+0.10
A=1.90 
câu b mình pó tay

Answer 2

a ) \(A=0,1+0,2+...+0,19\)

\(A=\left(0,1+0,2+...+0,9\right)+\left(0,10+0,11+...+0,19\right)\)

\(A=0,1\times\left(1+2+...+9\right)+0,1\times\left(1+1,1+...+1,9\right)\)

\(A=0,1\times45+0,1\times14,5\)

\(A=0,1\times\left(45+14,5\right)\)

\(A=0,1\times59,5\)

\(A=5,95\)

b ) \(B=\left(2017\times2016+2014\times2015\right)\times\left(1+\frac{1}{2}\div1\frac{1}{2}+1\frac{1}{3}\right)\)

\(B=\left(2017\times2016+2014\times2015\right)\times\left(1+\frac{1}{2}\div\frac{3}{2}+\frac{4}{3}\right)\)

\(B=\left(2017\times2016+2014\times2015\right)\times\left(1+\frac{2}{6}+\frac{4}{3}\right)\)

\(B=\left(2017\times2016+2014\times2015\right)\times\frac{8}{3}\)