4 câu ạ, giúp với em với :((

Đáp án:

a) $35,5.35,5+71.64,5+64,5.64,5$.

$\begin{array}{l}=35,5.35,5+64,5.(71+64,5)\\=35,5.35,5+135,5.64,5\\=35,5.35,5+(35,5+100).64,5\\=35,5.35,5+35,5.64,5+64,5.100\\=35,5.(35,5+64,5)+64,5.100\\=35,5.100+64,5.100\\=100.(35,5+64,5)\\=100.100\\=10000\end{array}$

b) $8,5.8,5-2.8,5.3,5+3,5.3,5$.

$\begin{array}{l}=8,5.8,5-7.8,5+3,5.3,5\\=8,5.(8,5-7)+3,5.3,5\\=8,5.1,5+3,5.3,5\\=(5+3,5).1,5+3,5.3,5\\=5.1,5+3,5.1,5+3,5.3,5\\=5.1,5+3,5.(1,5+3,5)\\=5.1,5+3,5.5\\=5.(1,5+3,5)\\=5.5\\=25\end{array}$

c) $10+(-5,3)+3,1+(-4,7)$.

$\begin{array}{l}=10+3,1+(-5,3-4,7)\\=10+3,1+(-10)\\=(10-10)+3,1\\=3,1\end{array}$

d) $-73,8.0,91+(-0,91).26.2$

$\begin{array}{l}=73,8.(-0,91)+(-0,91).26,2\\=-0,91.(73,8+26,2)\\=-0,91.100\\=-91\end{array}$