A=71 38/45-(43 8/45 + 1 17/57)

=( 71 38/45-43 8/45 )+ 1 17/57

= 28 2/3 + 1 17/57

= 29 55/57

\(A=71\frac{38}{45}-\left(43\frac{8}{45}+1\frac{17}{57}\right)\)

\(A=\frac{3233}{45}-\left(\frac{1943}{45}+\frac{74}{57}\right)\)

\(A=\frac{3233}{45}-\frac{1943}{45}-\frac{74}{57}\)

\(A=\frac{86}{3}-\frac{74}{57}=\frac{520}{19}\)

giải

71/38/45-(43/8/45-1/17/57)

=71/38/45-43/8/45+1/17/57

=28/30/45+1/17/57

=1708/57

\(71\dfrac{38}{45}-\left(43\dfrac{8}{45}-1\dfrac{17}{57}\right)\)

\(=71\dfrac{38}{45}-43\dfrac{8}{45}+1\dfrac{17}{57}\)

\(=28\dfrac{2}{3}+1\dfrac{17}{57}=\dfrac{86}{3}+\dfrac{74}{47}=\dfrac{1708}{57}\)

Chúc bạn học tốt!!!

\(B=71\dfrac{38}{45}-\left(43\dfrac{8}{45}-1\dfrac{17}{57}\right)\)
\(B=71\dfrac{38}{45}-43\dfrac{8}{45}+1\dfrac{17}{57}\)

\(B=\left(71\dfrac{38}{45}-43\dfrac{8}{45}\right)+1\dfrac{17}{57}\)
\(B=28\dfrac{2}{3}+1\dfrac{17}{57}\)
\(B=29\dfrac{55}{57}\)

\(71\dfrac{38}{45}-\left(43\dfrac{8}{45}-1\dfrac{17}{57}\right)\\ =71\dfrac{38}{45}-43\dfrac{8}{45}+1\dfrac{17}{57}\\ =\left(71\dfrac{38}{45}-43\dfrac{8}{45}\right)+1\dfrac{17}{57}\\ =28\dfrac{2}{3}+1\dfrac{17}{57}\\ =\dfrac{86}{3}+\dfrac{74}{57}\\ =\dfrac{1708}{57}\)

=71+38/45- 43+8/45 +1+17/57

=(71 \(\frac{38}{45}-43\frac{8}{45}\))+ 1+17/57=28+2/3+1+17/57=29+55/57=29/55/57

1670/57

1670/57

\(71\frac{38}{45}-\left(43\frac{8}{45}-1\frac{17}{57}\right)\)

\(=71\frac{38}{45}-43\frac{8}{45}+1\frac{17}{57}\)

\(=\frac{86}{3}+\frac{74}{57}\)

\(=\frac{1708}{57}\)

Hc tốt #