A=[3,08*(23+77)] + [17,12*(62+37+1)]
A=(3,08*100)+(17,12*100)
A=308+1712
A=2020
\(A=17,12\times62+3,08\times23+17,12\times37+3,08\times77+17,12\)
\(=\left(17,12\times62+17,12\times37+17,12\right)+\left(3,08\times23+3,08\times77\right)\)
\(=17,12\times\left(62+37+1\right)+3,08\times\left(23+77\right)\)
\(=17,12\times100+3,08\times100\)
\(=1712+308\)
\(=2020\)
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